Re: [Qgis-user] Projections

[Falk Huettmann]

Hi there, Mike et al,

thanks,
but if you check up with Thomas Alerstam  from Sweden - as a bird tracking
migration person you really ought to know those things and his entire
books/papers -
there is sufficient literature on the topic for years re. projections, e.g.
this one for starters.
https://www.researchgate.net/publication/12122402_Migration_Along_Orthodromic_Sun_Compass_Routes_by_Arctic_Birds

Some others are found with the navigation sciences, with sea turtle math
work (former Ram Myers) and then rocket and missile targeting of course.
It's usually not written though by geography or GIS experts. The Google
Earth maps boldly ignore the projection issue (as they are just a shiny
commercial PR tool).

Overall, for birds these days, the public resource question should sit on
CONSERVATION and sustainable management,
not ivory-tower questions. The latter have been done for centuries without
relevant outcome and progress.
Yes, the earth is round and an optimal route exist, but now what ? Birds
know and used that for millennia and their presences show it no other..
Data exist to that degree.
Other problems are more relevant these days.

A nice question why after 100 years of research on bird migration,
state-funded with $Mio's, and with MPI and Movebank, ICARUS etc
no readily available solution or answer exist in R or GIS etc.

That's my opinion and answer on your question. Feel free to follow up as
needed.

Best regards
   Falk Huettmann PhD, Professor
 Uni of Alaska Fairbanks


On Wed, Oct 21, 2020 at 11:53 PM MIKE MCGRADY 
wrote:

> As far as I can recall, few studies of long-distance migratory species
> state what projections are used.  Is there any published study of the
> effect of projections on analyses of animal movement?
>
> M
>
> M. J. McGrady
> Am Rosenhugel 59
> A-3500 Krems
> Austria
>
> --
> *From:* Qgis-user  on behalf of Hernán
> De Angelis 
> *Sent:* Thursday, October 22, 2020 6:57 AM
> *To:* qgis-user@lists.osgeo.org 
> *Subject:* Re: [Qgis-user] Projections
>
>
> Mike
>
>
> For measuring the kind of distances you are mentioning I would suggest
> using ellipsoidal (geodetic) distances rather than projected distances.
> This is because projected distances can become very inaccurate over large
> regions (depending on the particular projection of course).
>
>
> If measuring areas is important consider an equal area projection, like
> Albers for example, not a conformal one like Lambert.
>
>
> Hope this helps.
>
>
> /H.
>
>
>
>
> On 2020-10-22 07:43, MIKE MCGRADY wrote:
>
> I have data on tracked migratory birds, and want accurate measures of
> distance travelled during migration and areas of summering and wintering
> ranges.  These birds are summering in central Asia (mostly Kazakhstan and
> southern Russia), and wintering in Arabia.  Any advice on which projection
> to use?  My guess is Lambert conformal conic.  I'd really like to avoid
> using different projections for different phases of the birds' annual
> cycle, unless absolutely necessary.
>
> M. J. McGrady
> Am Rosenhugel 59
> A-3500 Krems
> Austria
>
> ___
> Qgis-user mailing listqgis-u...@lists.osgeo.org
> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
>
> ___
> Qgis-user mailing list
> Qgis-user@lists.osgeo.org
> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

Re: [Qgis-user] wishing for accurate lattitude/longitude from a cell phone

[Falk Huettmann]

Dear Jochen et al,

...thanks,
but it is 100% incorrect that Google Earth made satellite data available,
and/or for free, e.g. Landsat.
The opposite is the case (Landsat was made open by the Clinton
administration etc much before that, by law. It's widely paid by US tax
money btw) ;
so Google Earth just used a nice and shiny PUBLIC image set and copyrighted
it, value-added as a map background; more or less.
There are no 8 bands in the Google Earth Landsat set to use; just a flat
image file!
What's the progress other than the hype and them selling public stuff and
making it hard for GIS users etc ?
Who owns the space, the satellites ?

It's also incorrect to call Google Earth and its format a GIS; Google Earth
is just a visualizing tool, kmz is pretty awful for any serious GIS work
and database work (just like shapefiles are, even worse in Geodatabases;
all commercial btw
and based on dBASE style).

OpenStreetMaps cannot copyright words, as a product (an Open Street Map
that is, public common words found in any dictionary).
Apple does not own apples neither, nor snow leopards.

If somebody occupies, measures and uses public spaces, and then gets 'the
best' (hi res) data on the market, e.g. for roads,
that's clearly a monopoly, and should be treated as such, and with ethics.
It has many many implications in capitalism and worse, e.g.
https://www.gnu.org/philosophy/why-copyleft.en.html

So the easier,  and the better a format is described, the better for
everybody to use (if that's the purpose).
ISO comes to play, or VM, GNU etc .

We have seen very bad things last 40 years in the GIS world, and it's
little progress.
Certainly true for the EU and the German Katasteraemter, or EU Remote
Sensing or EU science (see Max Planck Institutes etc, Fisheries data,
cancer data).
What they call open access usually is not, and very clumsy at best; widely
underachieving for decades.

It is very important here to understand and perceive those things
correctly, because
otherwise we end up with more private and commercial intrusions.
Bad impacts can be seen world-wide already, all the time.
GARMIN is among them; just see COVID examples.

QGIS is a shining example and outlier, beyond R (not a GIS btw).

Any public librarian can tell you their stories about it (and consider many
libraries being short-handed most times, hardly afloat for money).

It's a very important subject, Just think of use of hi res data for drones,
the decaying public good, global society etc
An example here: https://en.wikipedia.org/wiki/Bowling_Alone

That's my experience on the topic and why I shared it here in some detail;
thanks.

Keep me posted please; very best
   Falk Huettmann PhD, Professor
 University of Alaska Fairbanks










On Mon, May 25, 2020 at 12:28 PM  wrote:

> Hi,
>
> while I agree that there are lots of bad examples of proprietary formats,
> I want to say a few words to some of your examples:
> It is true that OpenStreetMap data is difficult to handle -  this is not
> because it is closed, but because it is open. When the project was started
> the goal was to make it as easy as possible for people to contribute to the
> dataset. Thus there are few restrictions which makes it difficult to render
> or process the data. But the alternative would probably have been to
> discuss the data format for years instead of building an amazing open
> dataset...
>
> While Garmin makes it difficult to upload custom maps to their units as
> Nicolas wrote, many of their devices can be accessed as a USB drive and
> waypoint/track data can simply be copied as .GPX-files. I have seen many
> devices needing special software to transfer data, so this is actually easy.
>
> When Google Earth first came to be, it was amazing - access to satellite
> or aerial imagery had been expensive and difficult before. So I don't have
> a problem with the fact that Google didn't make the data available for
> everyone to use (probably license restrictions prohibit this).
>
> Text files aren't often that simple - there are different encodings for
> example which aren't advertised in the files, so you often have to guess to
> get special characters right. They have no inbuilt validity checks, so
> errors can not be easily recognised. In most use cases, structured (XML)
> formats are preferable. And especially for large datasets, you get much
> better performance and functionality using other formats like Geopackage.
> The point in my opinion is that a format is open and well documented.
>
> Of course it is great if geodata is available to the public. In the EU,
> there has been a lot of movement in the last years with more and more data
> becoming available under open licenses, let's hope this continues.
>
> Regards,
> Jochen
>
> Am 25.05.20 um 20:55 schrieb Falk Huettmann:
>
> Dear Chris et al,
>
> ...by using certain specific/clumsy forma

Re: [Qgis-user] wishing for accurate lattitude/longitude from a cell phone

[Falk Huettmann]

Dear Chris et al,

...by using certain specific/clumsy formats -poorly documented ones - you
can virtually exclude
people from data and from Remote Sensing data and GPS etc.
Google Earth as a  classic example, and GARMIN as another, or ESRI files,
certainly NetCDF or many R packages even.

In reality, you will see that all what is shiny and new - in demand- is to
be sold, and usually not well publically shared.
It takes many steps to get around it, if even that.

While I have used OpenStreet maps, it was very clumsy; more bad examples
exist, e.g. lack of metadata.
Whatever companies tell ya, they want to sell more stuff (sell PR, or might
face bankruptcy otherwise).

And it is my hope that with QGIS we get to open access and open source,
of these data, and any other.

My format of choice is plain and simple ASCII text files for those reasons,
perhaps using the
Virtual Machine as a platform forever (well, as long as that is reasonable,
but not commercially driven).

Keep me posted please; very best & thanks
 Falk Huettmann


On Mon, May 25, 2020 at 10:19 AM chris hermansen 
wrote:

> Falk and list;
>
> On Mon, May 25, 2020 at 10:48 AM Falk Huettmann 
> wrote:
>
>> Dear List,
>> I think these GPS high resolution suggestions are great;
>> thanks.
>>
>> But my real interest/question here is, how can we bring it home to QGIS ?
>>
>> I see GARMIN essentially trying to sell and impose on us their GIS system,
>> same applies to OpenStreet Maps etc etc. So they try to privatize
>> geography and public space and information,
>> which I am mostly opposed to.
>>
>
> How is OpenStreetMap (I assume when you say "OpenStreet Maps" you mean
> "OpenStreetMap") trying "to privatize geography and public space and
> information"?   Not trying to start an argument here; this just seems
> completely contrary to what I know of OpenStreetMap, whose data is licensed
> under https://opendatacommons.org/licenses/odbl/1.0/
>
>
>> Instead, I wonder how we can use QGIS and release the commercial
>> data into Open Source and public use ?
>> That's for HIGH RESOLUTION data discussed here.
>>
>> Thanks for such questions and solutions.
>>
>
> [stuff deleted]
>
>
> --
> Chris Hermansen · clhermansen "at" gmail "dot" com
>
> C'est ma façon de parler.
>
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

Re: [Qgis-user] wishing for accurate lattitude/longitude from a cell phone

[Falk Huettmann]

Dear List,
I think these GPS high resolution suggestions are great;
thanks.

But my real interest/question here is, how can we bring it home to QGIS ?

I see GARMIN essentially trying to sell and impose on us their GIS system,
same applies to OpenStreet Maps etc etc. So they try to privatize geography
and public space and information,
which I am mostly opposed to.

Instead, I wonder how we can use QGIS and release the commercial
data into Open Source and public use ?
That's for HIGH RESOLUTION data discussed here.

Thanks for such questions and solutions.

Very best
   Falk Huettmann PhD, Professor
Uni of Alaska Fairbanks


On Mon, May 25, 2020 at 9:41 AM Kirk Schmidt 
wrote:

> Hi List:
>
> In my experience, the key is writing output in rinex format so that the
> rover data can be corrected either using PPP if you can collect your GPS
> data over and extended period of time or use pre-existing (or self
> deployed) base station over a know coordinate to provide correction data.
> Most consumer grade units output the final position solution, not detailed
> satellite data which is required for followup processing.
>
> Kirk Schmidt
> On 5/25/2020 2:31 PM, chris hermansen wrote:
>
> Martin and list,
>
> To me, in general, I think I would try to go with a Raspberry Pi based
> solution.  The hardware isn't all that expensive and the easy ability to do
> stuff directly with the output of the device in Python or some other
> programming language seems to be preferable to messing around with Android
> or iOS applications.
>
> One of many articles that may be of interest
> https://learn.adafruit.com/adafruit-ultimate-gps-on-the-raspberry-pi?view=all
>
> On Mon, May 25, 2020 at 9:25 AM Martin Weis 
> wrote:
>
>> Dear list,
>>
>> I would like to add some things here, since I am trying to use RTK GPS
>> in the field with mobile devices.
>>
>> > 1) Accuracy of GPS Devices
>>
>> RTK GPS or any more precice GPS technology will be external, you cannot
>> get around the missing measurements and lack of algorithms in consumer
>> grade chips.
>>
>> Then it depends on the capabilities of the device to receive satellites
>> of all systems (one or multiple frequencies/signals) and be able to
>> apply correction data (a question of algorithms). For better equipment
>> the prices rise quickly.
>>
>> There are some low cost devices evolving, a new chip was recently
>> announced: Skytraq PX1122R for about $100. Could be tested with a break
>> out board and antenna, e.g. see board at navspark shop. The module even
>> supports PPP, which might be especially interesting where mobile network
>> is not available.
>>
>> https://navspark.mybigcommerce.com/px1122r-evb-px1122r-multi-band-quad-gnss-rtk-evaluation-board/
>>
>> Other low cost solution were mentioned (emlid/REACH, Catalyst, etc).
>>
>>
>> Am 23.05.20 um 21:51 schrieb Michael.Dodd:
>> > One app that claims to do a lot of what high precions gps does is>
>> Mobile Topographer Free – Apps on Google Play
>>
>> > 2) Software
>>
>> On Android I was able to get the external signal into the system, you
>> need the app "Bluetoth GPS" (or similar) or a USB2serial + app (better
>> avoid tiny plugs and large cables during field work). Additionally you
>> need to override the internal GPS position with the Blue GPS App in the
>> developer settings (mock provider).
>>
>> My impression was, that most Android applications target the accuracy of
>> the device only, so e.g.
>>
>> * you cannot zoom to cm-levels, only ~100m
>> * not many proper GIS Apps are available, most are expensive
>> * Tracking usually does not rely on cm-grade positions, so the apps are
>> not made for it
>>
>> One particular thing is, that with high accuracy of the signal, an
>> internal computation in single precision float will not suffice (all
>> computations must be in double precision), and you may end up with a cut
>> off of the last position digits, e.g. if you have 8 digits, 4 before and
>> 4 after the decimal separator (e.g. in DDMM. format), then you end
>> up with coordinates cut down to 2-3 decimeters in the real world
>> (typical GPS mouse output, not so uncommon).
>>
>> So, looking into that aspect may be required, and only few Apps may
>> implement that (e.g. expensive "surveyor" apps for professionals? did
>> not test).
>> BTW, sponsoring the double accuracy implementation for QField is
>> welcome, as mentioned ot the webpage. It is already a very usable and
>> FLOSS GIS solution for the field, especially useful if you have a QGIS

Re: [Qgis-user] combining fragmented forests (RMG)

[Falk Huettmann]

Hi there,

greetings;
I have seen and done such things, a lot,
and I would like to give you a message of caution about it.

One serious problem is here that it includes error inconsistencies (sheet
edges vs sheet centers),
another one is about classes and patches that are incorrect to start with
(all sheets; merged or not).

In other words,
there are several types of errors in such 'technical artefacts' aka  merged
forest patch maps;
they "cannot be used for navigation", to put it politely.
It's a blurr of things, and a major problem with forest maps and forest
inventory maps out there.

I know of forest maps and regions that have accuracies of 40%, if
ground-truthed.
So yes, they look great on the screen and in GIS but are close to random
(50% accuracy)
if ever used and interpreted for applications.
Please be aware; happy to hear about a fix; beyond technical GIS ones, or
rubber sheeting.

Keep me posted please; thanks.
Very best
   Falk

PS There is currently no single accepted map of global forest cover;
FAO, IUFRO etc cannot really agree on such details whatsoever.
And yes, Remote Sensing products, LIDAR and air photo interpretation
can be rather poor for quality, usually they are.











On Wed, May 6, 2020 at 2:50 PM Michael Harte  wrote:

> Reiko,
>
> You could try something like this:
>
>
>1. Merge all forests into a single file (if you haven't already);
>2. Create a new field in the forests table called something like
>"border"
>3. Create lines that trace the panel boundaries, that separate the
>forests you want to join;
>4. Buffer each of those lines by some small distance  (try 1 meter);
>5. For each buffer "Select by location" all features in forests that
>intersect buffer;
>6. Use the field calculator in the table to enter a unique identifier
>for the selected features in the "border" field;
>7. Do this for each buffer;
>8. Dissolve the forest layer on the border field.
>
> Feel free to get in touch.
>
> Cheers,
>
> Mike
>
>
>
> Message: 1
> Date: Wed, 6 May 2020 14:55:30 -0400
> From: RMG  
> To: qgis-user@lists.osgeo.org
> Subject: [Qgis-user] combining fragmented forests
> Message-ID:
>
> 
> Content-Type: text/plain; charset="utf-8"
>
> Hello,
>
> I have five shapefiles that contain thousands of fragmented forests that I
> created from a NDVI raster of a large protected area in West Africa, which
> I separated into five panels. Now, how do I stitch thousands of the
> fragmented forests at the borders?
>
> Each shapefile's attributes have ID, count (number of units), area, and
> perimeter, so I can visually recognize which fragments need stitching, but
> because there are so many, I don't think I can do it manually.
>
> Any help would be appreciated.
>
> Best wishes,
>
>
> Reiko Matsuda Goodwin
> Comoé Monkey Project  
> 
> Guenon Conservation 
> Community 
> 
> -- next part --
> An HTML attachment was scrubbed...
> URL: 
> 
>  
> 
>
> --
>
> ___
> Qgis-user mailing list
> Qgis-user@lists.osgeo.org
> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

Re: [Qgis-user] Working with DEMs

[Falk Huettmann]

Hi there,

thanks,
just to elaborate, for those who are interested:

(I would like to see the study that has compared those DEM products;
it matters a lot for climate models, for instance; happy to read the
citations).

Getting precise DEMs remains a massive struggle, regardless of what people,
govs and products claim.
What is needed is a 'Quality Standard', as well as metadata (FGDC, ISO) for
transparency.
It's as simple as that.
While in QGIS it's not our maintastk, it matters a lot and for
added value.  So the more we can push for it, the  better, and include such
tools.

Why are DEMs from contour lines 'good' ?
Because they come from an era where people worked more precise and used
analoge methods,
e.g. digitizing drums.

For your own quality control, compute manually slope2 (=2nd derivative)
from a DEM and see what you get.
If you see irregularities, lines and tiles something is rather odd, caused
by the DEM production process.

Very best
   Falk Huettmann









On Mon, Dec 16, 2019 at 9:44 AM Nicolas Cadieux <
nicolas.cadi...@archeotec.ca> wrote:

> Hi,
>
> I agree Falk that DEMs made from contour lines have their problems
> (stepped slopes, flat areas, elevation drops in lakes...).  Depending on
> the input data, they can still be a very accurate model for elevation.
> I tested the SRTM, NASADEMs, Alos, ASTER and the CDED (Canadian Digital
> Elevation Data) in Canada with LiDAR in various environments.
> Surprisingly, The CDED, made from 50k contour line are still the most
> accurate elevation wise.
>
> Nicolas Cadieux
>
> On 2019-12-12 5:29 p.m., Falk Huettmann wrote:
> > Hi there,
> > my comment to that DEM/contour profile question is:
> > if you have a contour map, it's usually a pretty poor DEM and
> representation
> > of reality, e.g. nature has no lines...
> > If you then create a raster (back again) from the contour, it gets
> circular
> > and even worse = pretty odd. A double whammy.
> >
> > So I would never ever recommend doing this, in case the DEM or Contour
> data
> > are to show any meaningful ground information, or are to be used for
> such.
> >
> > That's my view.
> > Very best
> > Falk Huettmann
> >
> > On 12/12/19, Håvard Tveite  wrote:
> >> On 11.12.2019 15:14, kirk wrote:
> >>> Hi Bernd. You will have to create a raster dem from your contour data.
> >>> First extract nodes from lines and ensure the elevation field is
> >>> extracted.
> >>> Once you have the point data, you can generate a raster using a tin or
> >>> spline interpretation.
> >> You can also create the raster DEM directly from the contour data
> >> (for instance with the "TIN interpolation" algorithm, using your
> >> contour layer as "Structured lines").
> >>
> >> Håvard
> >>
> >>> The resulting raster should work with the plugin.
> >>>
> >>>
> >>>
> >>> Sent from my Samsung Galaxy smartphone.
> >>>
> >>>  Original message 
> >>> From: Dave Gardiner <2dave.gardi...@gmail.com>
> >>> Date: 2019-12-10 11:43 PM (GMT-05:00)
> >>> To: qgis-user@lists.osgeo.org
> >>> Subject: [Qgis-user] Working with DEMs
> >>>
> >>> I am trying to create a geological cross section using the qProf
> plugin.
> >>> This
> >>> asks for the source of the DEM on which to base the elevations. My
> problem
> >>> is my source for the elevation data is vector layer of contours
> imported
> >>> from a csv file. How do I create a DEM from this please?
> >>>
> >>>
> >>>
> >>> --
> >>> Sent from: http://osgeo-org.1560.x6.nabble.com/QGIS-User-f4125267.html
> >>> ___
> >>> Qgis-user mailing list
> >>> Qgis-user@lists.osgeo.org
> >>> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> >>> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
> >> ___
> >> Qgis-user mailing list
> >> Qgis-user@lists.osgeo.org
> >> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> >> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
> > ___
> > Qgis-user mailing list
> > Qgis-user@lists.osgeo.org
> > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
>
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

Re: [Qgis-user] Working with DEMs

[Falk Huettmann]

Hi there,
my comment to that DEM/contour profile question is:
if you have a contour map, it's usually a pretty poor DEM and representation
of reality, e.g. nature has no lines...
If you then create a raster (back again) from the contour, it gets circular
and even worse = pretty odd. A double whammy.

So I would never ever recommend doing this, in case the DEM or Contour data
are to show any meaningful ground information, or are to be used for such.

That's my view.
Very best
   Falk Huettmann

On 12/12/19, Håvard Tveite  wrote:
> On 11.12.2019 15:14, kirk wrote:
>> Hi Bernd. You will have to create a raster dem from your contour data.
>> First extract nodes from lines and ensure the elevation field is
>> extracted.
>> Once you have the point data, you can generate a raster using a tin or
>> spline interpretation.
>
> You can also create the raster DEM directly from the contour data
> (for instance with the "TIN interpolation" algorithm, using your
> contour layer as "Structured lines").
>
> Håvard
>
>> The resulting raster should work with the plugin.
>>
>>
>>
>> Sent from my Samsung Galaxy smartphone.
>>
>>  Original message 
>> From: Dave Gardiner <2dave.gardi...@gmail.com>
>> Date: 2019-12-10 11:43 PM (GMT-05:00)
>> To: qgis-user@lists.osgeo.org
>> Subject: [Qgis-user] Working with DEMs
>>
>> I am trying to create a geological cross section using the qProf plugin.
>> This
>> asks for the source of the DEM on which to base the elevations. My problem
>> is my source for the elevation data is vector layer of contours imported
>> from a csv file. How do I create a DEM from this please?
>>
>>
>>
>> --
>> Sent from: http://osgeo-org.1560.x6.nabble.com/QGIS-User-f4125267.html
>> ___
>> Qgis-user mailing list
>> Qgis-user@lists.osgeo.org
>> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
>> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
>
> ___
> Qgis-user mailing list
> Qgis-user@lists.osgeo.org
> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

Re: [Qgis-user] Handling a large number of raster layers with Qgis architectural limitations

[Falk Huettmann]

Dear Colleagues, Patrick,

thanks, this is a VERY relevant issue, and might be the future concept for
GIS, of sorts (=more data volumes).
While I have no direct answer to your architecture question (sorry),
I have a sample dataset and application on the topic and can share it with
people as they see fit.
Here the manuscript and data, unpublished
https://www.earth-syst-sci-data-discuss.net/essd-2016-65/

The 104 GIS data layers (rasters) I can share via a google drive etc with
people on request and for more
progress and completion of the topic.

Arguably,
people are shopping around in the GIS world for a solution and platform
for such type of (massive multi) layer questions/analysis, and classic R
has usually a memory issue,
and supercomputing and 'the cloud' lacks the 'usual' GIS platform etc etc.
So here comes QGIS to the rescue, more or less
(consider Metadata creation in such projects also).
I am happy to learn.

Please keep me posted on this topic, offline as needed.

Thanks so much, very best
Falk Huettmann

On Wed, Nov 27, 2019 at 6:35 PM Patrick Dunford 
wrote:

> Hello,
>
> the issue is not with the performance drawing the raster, it is with the
> system only being able to have a certain number of file based rasters
> loaded in a project before it will crash.
> On 22/11/19 11:08 AM, Alexandre Neto wrote:
>
> AFAIK,
>
> WMST creates pyramids in cache as needed, hence it may do a better balance
> between disk usage and performance. You can control the number of pyramid
> layers you create and the compression format of it to save some space. But
> having raster files with 4000x4000 pixels with no pyramids will make a full
> read of the raster file to show even only a bit of it... That will make
> QGIS performance really poor.
>
> Thereºs this blog post from 2010 that does some comparison between several
> formats and their sizes and performances. It's in portuguese, but I think
> you can find ways of translating it.
>
>
> https://blog.viasig.com/2010/01/mosaicos-de-imagens-em-mapserver-com-gdal/
>
> Hope it helps
>
> Alexandre Neto
>
> On Thu, Nov 21, 2019 at 2:05 PM Patrick Dunford 
> wrote:
>
>> Building pyramids gobbles up heaps of disk space. I tried pyramids on 157
>> MB layer, which created an extra file 1.6 GiB.
>>
>> I can't see the WMTS building lots of temporary file pyramids using up
>> disk
>> On 18/11/19 10:50 PM, Alexandre Neto wrote:
>>
>> Hi Patrick,
>>
>> Sorry for asking, did you create pyramids (overlays) for your raster
>> "tiles"?
>>
>> See more information about pyramids on QGIS official documentation:
>>
>>
>> https://docs.qgis.org/3.4/en/docs/user_manual/working_with_raster/raster_properties.html#pyramids-properties
>>
>> To create pyramids on many files, it's probably better to use GDAL
>> directly to process all files in a folder:
>>
>> https://gdal.org/programs/gdaladdo.html
>>
>> My feeling is that the WMS service is doing that for you, and that's the
>> reason why it works well with a service.
>>
>> Alexandre Neto
>> QGIS Support
>> www.qcooperative.net
>>
>> ___
>> Qgis-user mailing list
>> Qgis-user@lists.osgeo.org
>> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
>> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
>
> ___
> Qgis-user mailing list
> Qgis-user@lists.osgeo.org
> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

Re: [Qgis-user] Nearest point on line

[Falk Huettmann]

Hi there, Christoph,

generally speaking: I have another perspective about it and would approach
your problem it in a different way:

Instead of pre-defined cut-offs (which are circular reasoning and are often
surprising when checked in real world and GIS)
I would simply run a 'proximity to' points vs line first. And then in the
resulting proximity table set a cut-off, select accordingly and see whether
this achieves the outcome wanted.

For pre-defined cut-offs, we call it usually 'geographic racism'.
Instead, we try to celebrate the gradient theory; when tested it often
works better in real life.
Worth a test.

Just an alternative thought to the problem at hand.

Thanks, best
 Falk Huettmann











On Tue, Oct 22, 2019 at 3:26 AM Christoph Jung  wrote:

> Thank you all for your answers. I played a bit with the nnjoins plugin,
> but Andrews‘ answer is exactly what I was looking for :)
>
> Sincerely,
> Christoph
>
> > Am 18.10.2019 um 20:50 schrieb Andrew McAninch  >:
> >
> > You can do this in the field calculator with the refFunctions plugin.
>  It gives you a function, geomnearest(), which will return the WKT geometry
> of the nearest line(or geomdistance() if you want to limit your search
> radius).  Then use the closest_point() function to find the nearest point
> on that line.  something like:
> >
> > closest_point(geom_from_wkt(geomdistance('lines','$geometry',10)) ,
> $geometry)
> >
> >
> > Andrew
> >
> >
> >
> > ‐‐‐ Original Message ‐‐‐
> >> On Thursday, October 17, 2019 11:51 PM, Christoph Jung <
> jagodki...@gmail.com> wrote:
> >>
> >> Hello list,
> >>
> >> Does QGIS has a function to calculate the nearest point on a line layer
> by a given point layer? In PostGIS i could query it with
> min(st_distance(...)) or st_closestpoint(...). But I miss such a function
> directly in QGIS (I just found the plugin Cloest Point, but it has some
> issues...).
> >>
> >> Sincerely,
> >> Christoph
> >>
> >> Qgis-user mailing list
> >> Qgis-user@lists.osgeo.org
> >> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> >> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
> >
> >
> ___
> Qgis-user mailing list
> Qgis-user@lists.osgeo.org
> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

Re: [Qgis-user] Upsampling TIN

[Falk Huettmann]

Hi,
I agree with Barend and Nicolas here.

It's a typical and essential question that we get all the time, like,
can we re-grid and subsample pixels ?
=>You can, technically, but you stay just within the same data,
and thus, create nothing new or meaningful.

In other words, it should not be done.

There is a lot wrong with re-sampling, gridding, within DEMs, with merging
grids,
reprojecting and interpolation surfaces. And GIS techs are pretty guilty of
that,
so are their supervisors.
The tools we provide should point that out clearly and not allow for it.

Key to those questions remain 'ethics', metadata of course (!) and then
always a comparison as a benchmark for
accuracy and to see the actual gain of such re-samplings.

(but let's agree that TINs are only one way of getting a surface, often not
the best one,
when compared to the 'truth'. Playing around with them for best output is
not a bad idea)

  Very best
    Falk Huettmann




On Fri, Oct 4, 2019 at 4:00 AM Nicolas Cadieux 
wrote:

> Hi,
>
> You cannot invent new data between point without doing an interpolation.
> Your choice of interpolation will determine the quality of this data.  The
> only way I can think of is to create a raster from this TIN.  Then,
> resample (re-interpolated) this raster with a finer pixel and then make a
> new TIN.  This may create a finer TIN but this will significantly alter the
> original data.  You would need to evaluate the results and keep a backup of
> the old files.
>
> Alternative, I would try with Mesh Lab.  It’s open source and probably has
> Mesh densification methods that would be more adapted.  Cloud Compare also
> has interesting algorithms.
> Nicolas
>
> > Le 4 oct. 2019 à 03:40, joolek  a écrit :
> >
> > Hi Experts,
> >
> > I've tried so many software's without success.
> > Is it possible to upsample existing TIN? What I mean is for example
> divide each triangle into two for example. Not interpolation but somehow...
> subdivide or add more vertices between existing one?
> > Thank you for all your time
> > J
> > ___
> > Qgis-user mailing list
> > Qgis-user@lists.osgeo.org
> > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
> ___
> Qgis-user mailing list
> Qgis-user@lists.osgeo.org
> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

[Qgis-user] QGIS in INSPIRE, QAntarctica etc (Metadata)

[Falk Huettmann]

Dear all,

as Paolo suggested,
I should ask the list, so here I do:

"QGIS does have support to metadata. In fact, INSPIRE EU officials have
run extensive tests, and it is more compliant than any other GIS".

Could somebody please point me to details and to follow up on  ?

There are four questions in this:
-what about the U.S. and China government and their buy-in with this, aka
none?

-if there is ISO compliance, how can there be different fractions  and some
being ignored
(e.g. FGDC and USGS)?

-I have 'good' ISO compliant xml metadata files for try out, but they are
not loading into QGIS qmd; we need a cross-platform approach to cater
biology, geology, geography and social data. How done ?.

-real-world example: Antarctica is to have mandatory data, and with
metadata; for global mankind. Norway runs and offers a QGIS-based Antarctic
concept, but widely without relevant metadata.
https://www.qgis.org/en/site/about/case_studies/antarctica.html
They would be a typical example for us; looks like a violation of the
Antarctic Treaty even; not ?

Thanks again, more later
Falk Huettmann PhD, Professor
 Uni of Alaska Fairbanks
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

Re: [Qgis-user] QGIS metadata options ? (Thanks; re-post)

[Falk Huettmann]

Dear Paolo et al,,

yeah, I see it (thanks, QMD format in Layer Properties with attributes) but
it's best to stay with the
standard, which is something like I mentioned earlier; the precise XML
details matter for parsing and compliance
across platforms and tools (instead of :inventing own metadata formats).

I am still catching up with this one
http://archaeogeek.github.io/qgis-uk-glasgow-2016-metadata/#/
But FAIR and INSPIRE are only covering the (small) EU market for name sake,
if even that;
whereas the U.S. (MORPHO-NCEAS, FGDC, USGS tools) and China/Asian matters
MUCH MORE.
e.g. https://github.com/NCEAS/morpho  and its repository used for U.S. NSF
and governments + libraries.

And the ocean applications are hardly there yet, or in climate change
mapping and modeling (just see IPCC for lack of ISO metadata).

Metadata is essential, also for, and with,  R code, phython workflows etc.

Sure, if there is interest, I would be delighted to talk to somebody in
more detail
and how to make it happen. Thanks.

Again, I am thinking here of geology, geography, climate, social sciences,
biological, remote sensing and model prediction data and work etc.
For starters, here is  https://www.itis.gov/  (which we use a lot for our
GIS work with biological species, and with metadata); Those things are to
be catered
in open source GIS works. I have not looked into the Google Cloud and
Amazon Cloud, yet.

Sorry to beat here a dead horse, but for governmental, contractor and
science projects and software, without metadata any GIS work is not
acceptable, nor serious.
So it really matters; I am specifically thinking here of publication
standards for high-impact journals, peer-review and reviewing.

Thanks, happy to provide input and expertise as you require for QGIS.
To me, metadata are an anti-corruption and transparency measure. I assume
the world needs those things these days...

Keep me posted please
   Falk Huettmann PhD, Professor
University of Alaska Fairbanks


On Fri, Sep 20, 2019 at 11:55 PM Paolo Cavallini 
wrote:

> Hi Falk,
> metadata are now in standard qgis, you'll find it in Layer>Properties.
> Please check and let us know. There is room for improvement, please
> consider supporting it.
> Cheers.
>
> On 17/09/19 09:14, Falk Huettmann wrote:
> > Hi there, QGIS community,
> >
> > very sorry,
> > but I am still struggling with xml ISO compliant FGDC metadata in
> > QGIS.
> >
> > I only see the great webpage on MetaEdit;
> > well, except, I cannot find it in the PlugIns and the
> >  website seems to be not supported anymore; no reply upon request.
> >  http://gis-lab.info/qa/metatools-eng.html
> >
> > I would welcome any suggestions here on what to do; big thanks.
> >
> > QGIS, like any GIS and software and data, cannot live without metadata
> > and such an editor.
> > Even more so, that's where Open Source can entirely outcompete
> > and winI am thinking here for instance of (biological species
> > taxonomy) survey data with GIS data sources all read-in automatically
> > for modeling and predictions; with automated workflows...and then
> > readily documented with XML metadata and parsed and presented in html,
> > for instance.
> >
> > See here a monopoly piece in gitub; how can that be linked with QGIS
> > effectively ?.
> > https://github.com/usgs/fort-pymdwizard/
> >
> > For projects - commercial and science-, compliant ISO metadata can be
> > the deal breaker
> >
> > And I think we should probably not work with 'homebrew' code and rely on
> it.
> >
> > Thanks so much again for any pointers; very best
> >   Falk Huettmann
> >
> >
> > ___
> > Qgis-user mailing list
> > Qgis-user@lists.osgeo.org
> > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
> >
>
> --
> Paolo Cavallini - www.faunalia.eu
> QGIS.ORG Chair:
> http://planet.qgis.org/planet/user/28/tag/qgis%20board/
> ___
> Qgis-user mailing list
> Qgis-user@lists.osgeo.org
> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

Re: [Qgis-user] Question about Weighting Power value when running Grid-Inverse Distance to a Power

[Falk Huettmann]

Dear Colleagues,

as we work on such topics ourselves,
let me point out please that those 'sophisticated methods' of interpolation
etc
have 100% nothing to do with climate, or temperature, and such units,
and likely are very misleading for outcome.

One may call it 'data smearing' but not more.

(Scientifically,
if we see it, we usually reject it in full;
student failed and publication rejected.
No kidding. Lots of literature on what I state here;
krigging being among the worse).

So I propose not to fall into that trap.

"It can be done" (Ronald Reagan)
Reply: " Yeah, technically, but if it's crap, no need to".
Coder's delight.

Very best
Falk Huettmann PhD, Professor
  Uni of Alaska Fairbanks

PS I am sorry to raise those issues sometimes,
but it matters for context and best performance
and tools + relevant progress.
Follow up as needed please.


On Tue, Sep 17, 2019 at 2:39 AM DelazJ  wrote:

> Hi,
> Tracking information from the Help button in the algorithm dialog led me
> to
> https://gdal.org/tutorials/gdal_grid_tut.html#inverse-distance-to-a-power
>
> Hope that helps,
> Harrissou
>
> Le mar. 17 sept. 2019 à 12:00, Daniel Zepeda Rivas 
> a écrit :
>
>> When using the Raster -> Analysis -> Grid (Inverse Distance to a Power)
>>
>> At the menu just before pressing run, can somebody please explain me the
>> effect of the "Weighting power" option in the interpolation process?
>>
>> I'm trying to make a temperature map based on points representing each
>> weather station, containing the yearly averages values of temperature, and
>> when moving the number from the 2 (set it by default) to 4, 6 or 10, the
>> map changes significantly
>>
>> ___
>> Qgis-user mailing list
>> Qgis-user@lists.osgeo.org
>> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
>> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
>
> ___
> Qgis-user mailing list
> Qgis-user@lists.osgeo.org
> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

[Qgis-user] QGIS metadata options ? (Thanks; re-post)

[Falk Huettmann]

Hi there, QGIS community,

very sorry,
but I am still struggling with xml ISO compliant FGDC metadata in
QGIS.

I only see the great webpage on MetaEdit;
well, except, I cannot find it in the PlugIns and the
 website seems to be not supported anymore; no reply upon request.
 http://gis-lab.info/qa/metatools-eng.html

I would welcome any suggestions here on what to do; big thanks.

QGIS, like any GIS and software and data, cannot live without metadata and
such an editor.
Even more so, that's where Open Source can entirely outcompete
and winI am thinking here for instance of (biological species taxonomy)
survey data with GIS data sources all read-in automatically  for modeling
and predictions; with automated workflows...and then readily documented
with XML metadata and parsed and presented in html, for instance.

See here a monopoly piece in gitub; how can that be linked with QGIS
effectively ?.
https://github.com/usgs/fort-pymdwizard/

For projects - commercial and science-, compliant ISO metadata can be the
deal breaker

And I think we should probably not work with 'homebrew' code and rely on it.

Thanks so much again for any pointers; very best
  Falk Huettmann
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

[Qgis-user] FH 3 questions (million points, metadata, projection bug); thanks

[Falk Huettmann]

Dear Colleagues,
a few questions if I may:

-I am doing 3 million points, overlays, reprojections and table edits,
 and an expensive GIS package failed on us 'esrliy' (I like this word, in
case it actually is one).
 So we ran it in QGIS and the entire project saved; hooray! THANKS
 Anyways, how about we want to run 6 million points in QGIS ?
 How to do it best ? Any advise ?

-we find a consistent bug in QGIS when using Mercator projection and with a
180 degree meridian.
 Chukotka peninsula data do not show up; perhaps you know of a cure ?
 I am happy to send you the shapefiles and grids to look at.

-I love MetaEdit; well, except, I cannot find it in the PlugIns and the
 website seems to be not supported anymore.
 http://gis-lab.info/qa/metatools-eng.html
 Any hints for ISO compliant XML metadata  editor with QGIS ? QGIS needs it.

Thanks so much again; very best
   Falk Huettmann





On Mon, Aug 26, 2019 at 9:43 AM Falk Huettmann 
wrote:

> Dear Kind Colleagues,
>
> thanks, I have a similar question, but with an opposite aim:
>
> We have two points,
> and want to connect them,
> but then, NOT with the most direct and shortest path.
> Rather, with the most meaningful and considerate one.
> Like,
> length is not to be penalized but other factors, habitats available,
> amount of pixels
> underneath etc.
> Perhaps even showing different scenarios (aka, many paths lead to Rome...)
> ?
> The path can consist of more than a line, an area connection let's say.
>
> So in other words: the optimization is NOT done by short distance.
>
> Would you have any ideas and suggestions on that ?
>
> Thanks so much for any input
>Falk Huettmann
>
>
>
>
>
>
> On Mon, Aug 26, 2019 at 2:07 AM Chintan Advani 
> wrote:
>
>> Hi guys,
>>
>> I have a shape file with set of points on a road network. I am trying to
>> find the shortest distance among these points using the shortest path tool.
>> I have tried using the distance matrix tool in QGIS but it gives eucledian
>> distance between these points whereas I am looking the path distance (based
>> on road network). Can someone please suggest some tool or technique that
>> can help me solve this problem?
>>
>> Thanks and Regards,
>> __
>> Advani Chintan Sanjeev
>> Research Scholar,
>> Civil Engineering and Build Environment,
>> Queensland University of Technology,
>> Brisbane-4000, Australia.
>> ___
>> Qgis-user mailing list
>> Qgis-user@lists.osgeo.org
>> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
>> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
>
>
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

Re: [Qgis-user] Distance matrix using shortest path (FH longest path and others)

[Falk Huettmann]

Dear all,
thanks indeed,
we want to optimize for the longest path, or the one with the most
habitat/pixels underneath,
or at least see all options.
It's opposite from 'minimizing'.
I am probably aware how it is computed, mathematically (=flip the
optimization),
but in case you already know or see a plug-in, or such tools and software
available please kindly advise.

Very best and thanks
  Falk

PS There is a lot of philosophy showing how utterly poor those optimization
and mindless cost/benefit tools perform in real life (=Pareto optimum
described as a 'brutal racist' tool etc
See failures of Economy or when it gets applied to humans).
It's also utterly harmful for wildlife corridors (as wildlife then is just
EXCLUDED and MINIMIZED,
instead of maximized. Just think of Movement Paths for Elephants and
computed with
Least-Cost Paths, or Circuitscape. It's pathetic. That's why economic
developers and NGOs like those tools so much.
So instead here we are looking for other options and readily-available
tools, ideally. QGIS could be a good platform for that.
Thanks.
All of this has real-world implications (urban planning, road projections,
logistics landscape design,
national park design etc)


On Mon, Aug 26, 2019 at 10:14 AM Nicolas Cadieux <
nicolas.cadi...@archeotec.ca> wrote:

> Hi,
>
> Shortest path analysis can be done by counting the number of nodes
> (connections or intersections) or by using a distance variable
> (traditionally length).  However, “length” can be anything.  It can be any
> combination of factors.  Therefore, if you can model the various factors in
> a single “length” variable, then you can find the best path for your
> model.  Some algorithm will give you all paths to one point, some only the
> shortest path, and some will permit you to use a maximum cut off (ie max
> radiation absorption dose if radiation is part of the model.)
>
> Nicolas
>
> Le 26 août 2019 à 13:43, Falk Huettmann  a écrit :
>
> Dear Kind Colleagues,
>
> thanks, I have a similar question, but with an opposite aim:
>
> We have two points,
> and want to connect them,
> but then, NOT with the most direct and shortest path.
> Rather, with the most meaningful and considerate one.
> Like,
> length is not to be penalized but other factors, habitats available,
> amount of pixels
> underneath etc.
> Perhaps even showing different scenarios (aka, many paths lead to Rome...)
> ?
> The path can consist of more than a line, an area connection let's say.
>
> So in other words: the optimization is NOT done by short distance.
>
> Would you have any ideas and suggestions on that ?
>
> Thanks so much for any input
>Falk Huettmann
>
>
>
>
>
>
> On Mon, Aug 26, 2019 at 2:07 AM Chintan Advani 
> wrote:
>
>> Hi guys,
>>
>> I have a shape file with set of points on a road network. I am trying to
>> find the shortest distance among these points using the shortest path tool.
>> I have tried using the distance matrix tool in QGIS but it gives eucledian
>> distance between these points whereas I am looking the path distance (based
>> on road network). Can someone please suggest some tool or technique that
>> can help me solve this problem?
>>
>> Thanks and Regards,
>> __
>> Advani Chintan Sanjeev
>> Research Scholar,
>> Civil Engineering and Build Environment,
>> Queensland University of Technology,
>> Brisbane-4000, Australia.
>> ___
>> Qgis-user mailing list
>> Qgis-user@lists.osgeo.org
>> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
>> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
>
> ___
> Qgis-user mailing list
> Qgis-user@lists.osgeo.org
> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
>
>
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

Re: [Qgis-user] Distance matrix using shortest path (FH longest path and others)

[Falk Huettmann]

Dear Kind Colleagues,

thanks, I have a similar question, but with an opposite aim:

We have two points,
and want to connect them,
but then, NOT with the most direct and shortest path.
Rather, with the most meaningful and considerate one.
Like,
length is not to be penalized but other factors, habitats available, amount
of pixels
underneath etc.
Perhaps even showing different scenarios (aka, many paths lead to Rome...) ?
The path can consist of more than a line, an area connection let's say.

So in other words: the optimization is NOT done by short distance.

Would you have any ideas and suggestions on that ?

Thanks so much for any input
   Falk Huettmann






On Mon, Aug 26, 2019 at 2:07 AM Chintan Advani 
wrote:

> Hi guys,
>
> I have a shape file with set of points on a road network. I am trying to
> find the shortest distance among these points using the shortest path tool.
> I have tried using the distance matrix tool in QGIS but it gives eucledian
> distance between these points whereas I am looking the path distance (based
> on road network). Can someone please suggest some tool or technique that
> can help me solve this problem?
>
> Thanks and Regards,
> __
> Advani Chintan Sanjeev
> Research Scholar,
> Civil Engineering and Build Environment,
> Queensland University of Technology,
> Brisbane-4000, Australia.
> ___
> Qgis-user mailing list
> Qgis-user@lists.osgeo.org
> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

[Qgis-user] QGIS under LINUX in a workflow

[Falk Huettmann]

Hi there,

if possible,
I would need and appreciate some pointers on how to run, and use, QGIS in
LINUX.
A Windows10 set-up with LINUX would be a good way to go for us.

(Sorry of that appears to be a simple question, but we need a workflow and
also
related to database handling, inputs and outputs via QGIS and with online
data grabs).

I would welcome any feedback and input, as you can.

Thanks in advance; very best
   Falk Huettmann

​
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

Re: [Qgis-user] Ordinary Kriging in QGIS

[Falk Huettmann]

Hi all,

Just now it comes to my attention (sorry):

last years I went to a statistical session where the ESRI coders of the
krigging module
talked about 'issues' of the implementation there, and it was beyond scary
for me
(=>assumptions, merging outputs, edge issues etc. Krigging as such is
pretty sensitive to
underlying assumptions and data).

So my question is:
what is the science-basis for krigging in QGIS ?

Or asked other way round:
how can it be assured that the krigged results are meaningful and correct ?

If there is none of such metrics to assure it, then it's just another of
the many
shiny tools and 'homebrews' (not peer-reviewed and QA'ed really) out there
that mis-inform.

Like well-shown with home range analysis, kernels, random number
generators, optimizations and many predictions and model
selection tools, one may then ignore those outputs for a serious analysis.

The initial idea of open source was arguably that those things can be
tested, and improved, yes ?

I am open to hear feedback, examples and ideas for a betterment.

Thanks so much; kind regards
     Falk Huettmann



On Wed, Jun 27, 2018 at 11:39 PM, PARESH CHAUKHANDE <
paresh.chaukha...@gmail.com> wrote:

> Hello,
>   I am using QGIS v3.0.3 on macOSX(High Sierra).
>   I want to do ordinary kriging in QGIS.
>   I have 13 data points representing a state of yield attributes of
> agricultural crops. I am also having .shp files of states. I am doing
> following steps:
>   Processing> Toolbox> SAGA> Ordinary Kriging. The process runs OK and
> two new layers are created called Quality Measure and Prediction, but both
> these layers are invisible or show no information.
>   Kindly help me on these issues.
>   Thank you.
>
>
> Sincerely yours,
>
> PARESH CHAUKHANDE
>
> ___
> Qgis-user mailing list
> Qgis-user@lists.osgeo.org
> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
>
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

[Qgis-user] 104 layers global coverage into QGIS ... Re: Plugin Installation Issue: OpenLayers

[Falk Huettmann]

Dear Colleagues,

we currently have compiled 104 GIS layers open access, worldwide, on a 1km
pixel scale as tiffs.

These are habitat, climate and socio-economic data from various sources.

It's currently with a manuscript in review (see here in the appendix, if
interested
http://www.earth-syst-sci-data-discuss.net/essd-2016-65/).
It's a pre-print for public review with the ESSD journal.

Anyways,
my questions to you are:
-how can those data be served best to support QGIS, e.g. as a package or
plugin,
 and is that needed and wanted ?
-what other data sources of that level exist and how to co-arrange ?
-how to make it dynamic so that other people can add and contribute +
update ?

Another (species) data source is GBIF.org (an R package exist there but a
QGIS one would be  a most excellent idea, e.g. to wrestle the entire data
set in one shot!).
Movebank is another one, but it's certainly not Open Access; too bad on
them.

(I am sure you have seen the Antarctic version of QGIS with data, run from
Norway).

Funding remains a key question to get this done; my guess.
Perhaps the Academies of Sciences can take that on, serving the wider
public,
for a change ?

Happy to learn your thoughts and suggestions.

Thanks so much; kind regards
 Falk Huettmann

Falk Huettmann PhD, Associate Professor
-EWHALE lab-
University of Alaska Fairbanks (UAF)
Fairbanks Alaska 99775 USA
Email fhuettm...@alaska.edu
Tel. +1 907 474 7882

On Mon, Jul 3, 2017 at 9:37 AM, Matthias Kuhn <matth...@opengis.ch> wrote:

> 1. Better use QuickMapServices (or even better the integrated XYZ
> possibilities through the browser)
>
> 2. Check your proxy settings
>
>
>
> On 7/3/17 7:08 PM, Nate Cousineau wrote:
>
> Here is the message from the log right after the installation failed:
>
>
>
> 2017-07-03T13:07:33 1 Network request http://plugins.qgis.org/
> plugins/openlayers_plugin/version/1.4.3/download/ timed out
>
>
>
> *From:* Qgis-user [mailto:qgis-user-boun...@lists.osgeo.org
> <qgis-user-boun...@lists.osgeo.org>] *On Behalf Of *Matthias Kuhn
> *Sent:* Monday, July 03, 2017 12:47 PM
> *To:* qgis-user@lists.osgeo.org
> *Subject:* Re: [Qgis-user] Plugin Installation Issue: OpenLayers &
>
>
>
> Hi Nate,
>
> The error message here is unrelated to the two plugins you mentioned.
>
> Can you go to the plugin manager, make sure these plugins are activated
> and check if you have any other message there?
>
> Regards
>
> Matthias
>
>
>
> On 7/3/17 3:40 PM, Nate Cousineau wrote:
>
> I am using QGIS 2.18.10 on Windows. Below is the error message from the
> log:
>
>
>
> 2017-07-03T09:39:03   1  Failed to load
> C:/PROGRA~1/QGIS2~1.18/apps/qgis/plugins/globeplugin.dll (Reason: Cannot
> load library C:/PROGRA~1/QGIS2~1.18/apps/qgis/plugins/globeplugin.dll:
> The specified module could not be found.)
>
>
>
> Sorry for not providing enough information initially. I am new to all this.
>
>
>
> Thanks,
>
>
>
> [image: cid:662EF3C8-BB6C-426B-81CE-D65E482964E4@hsd1.fl.comcast.net.]
>
> *Nate Cousineau*
>
> Program Officer
>
> www.quantumfnd.org
>
> 561-832-7497 <(561)%20832-7497>
>
>
>
> 2701 N. Australian Ave., Suite 200
>
> West Palm Beach, FL  33407
>
>
>
>
>
>
>
> -Original Message-
> From: Qgis-user [mailto:qgis-user-boun...@lists.osgeo.org
> <qgis-user-boun...@lists.osgeo.org>] On Behalf Of Richard Duivenvoorde
> Sent: Sunday, July 02, 2017 4:05 AM
> To: qgis-user@lists.osgeo.org
> Subject: Re: [Qgis-user] Plugin Installation Issue: OpenLayers &
>
>
>
> On 30-06-17 21:33, Nate Cousineau wrote:
>
> > Greetings,
>
> >
>
> > I keep receiving an error when trying to install either OpenLayers
>
> > Plugin or QuickMap Services. Any advice is greatly appreciated.
>
>
>
> Start with telling us which versions of QGIS en Operating System your are
> working with.
>
>
>
> AND what exactly 'an error' means: copy paste the error message you see
> for example
>
>
>
> without this info we can not help you.
>
>
>
> Regards,
>
>
>
> Richard Duivenvoorde
>
> ___
>
> Qgis-user mailing list
>
> Qgis-user@lists.osgeo.org
>
> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
>
> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
>
>
>
>
> ___
>
> Qgis-user mailing list
>
> Qgis-user@lists.osgeo.org
>
> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
>
> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
>
>
>
>
>
> ___
> Qgis-user mailing list
> Qgis-user@lists.osgeo.org
> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
>
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

Re: [Qgis-user] Principal Component Analysis ?

[Falk Huettmann]

Hi,

thanks but nope:

CANOCO comes from the 1970s and is widely outdated by now,
and not achieving (much).
Just a few botanists (=not trained statisticians or coders) still use it,
if at all.
It usually asks the wrong questions and
uses pretty old methods that are widely improved by now,
e.g. machine learning. It all sits there instead, inference from
predictions. Many publications on that matter.
Sorry (any programmer knows it that machine learning performs 'very high').
Like with LMs, GLMs and AIC, p-values or Bayesian stuff, CANOCO does not
generalize nor predict so well.

R is free, a hodgepodge of sorts, and thus, the cutting edge stuff does NOT
all sit in R (high quality swords have a price, sorry).
It's reality. Google etc are not programmed in R or with R for good reasons.
Perhaps a certain blend is helpful, agreed, but hardly anything else.
R packages also tend to suffer from poor conceptual reviews, e.g. what for
and why ?

Again,
please be aware about such things.
Just because it's statistics, coded by your good buddy, freeware, R (or
QGIS), it's not all
automatically good; often the opposite is the case.

It's a fact and the crux you deal with here.
A so-called hijacking by some coders and their mindsets; we saw it many
times before,
and it's self-serving.
CANOCO is a great example for that.

Kind regards
   Falk

Falk Huettmann PhD, Associate Professor
Uni of Alaska Fairbanks UAF




On Fri, Jun 23, 2017 at 11:56 AM, Nicolas Cadieux <
nicolas.cadi...@archeotec.ca> wrote:

> Hi,
>
> I am not at what needs to be analyzed in this case but yes, canonical
> analysis needs to be well understood before being used.
>
> You can go to Pierre Legendre and Louis Legendre, Numerical Ecology, for
> help.  P Legendre also has a book on Spatial analysis in R that can be
> found.
>
> Cheers
> Nicolas
>
> P.S.
>
> As far as statistical software, R is unbeatable for cutting edge sciences.
> It is scary because it's a statistical language before being a statistical
> software.  But I agree, some statistics are implement in GIS software
> without any thought.
>
> Le 23 juin 2017 à 15:11, Falk Huettmann <fhuettm...@alaska.edu> a écrit :
>
> Hi there,
>
> in my view and if I may comment here:
> while R is scary (as stated below),  so are probably many of the wrapped R
> packages really,
> PCAs are even more scary, and their underlying mindsets,
> and the real horror starts when such things get
> implemented into 'homebrews' and such tools, or
> into QGIS and just as point and klick.
>
> As a rule, I would highly suggest to stay clear of such efforts and
> concepts.
> It's no good science, and not much defendable. Unless well thought out,
> it harms the product and reputation you want to create.
> (for a bad example see Krigging in some major commercial GIS...
>  We have seen such things many places).
>
> There should first be a good debate about statistics, if pursued as tools
> in QGIS etc.
> Arguably, unless it's predictive (for inference etc) it has no much value
> these days anymore.
>
> Agreed,
> it's a tragedy of our time that such old things still happen, all the time,
> and in the sciences.
> But it ain't no good, really, and is no good progress. My word for it.
>
> (I also agree that it is good to keep avenues open for such
> work, as an option and for people who know what they are doing and why;
> sure.
> But not more than that. Many bad examples exist all over for decades)
>
> Feel free to follow up as needed; kind regards
>Falk Huettmann
>  Uni of Alaska Fairbanks
>
>
> On Fri, Jun 23, 2017 at 10:57 AM, Nicolas Cadieux <
> nicolas.cadi...@archeotec.ca> wrote:
>
>> Hi,
>> You can use R for PCA.
>> Use the R Commander package to add a GUI.  R can be scary at first.
>> Nicolas
>>
>> Le 23 juin 2017 à 11:03, image [via OSGeo.org] <[hidden email]
>> <http:///user/SendEmail.jtp?type=node=5325361=0>> a écrit :
>>
>> Good afternoon,
>>
>> i'm working on windows with several opensource tools (qgis, otb,
>> grass...),
>>
>> I generated several OTB texture indices. Now, i want to evaluate the
>> information 's redundancy thanks to a Principal Component Analysis.
>>
>> => Is it possible to do that with some opensource tools (otb? qgis?
>> grass?) Moreover, I would like set a mask AND set a spectral subset (in
>> order to ignore some indices bands which seems "strange" and not relevant
>> to introduce into the process).
>>
>> Could you throw light for me?
>>
>> In advance, thank you very much for your help.
>>
>> Kind regards.
>>
>> --
>> If you reply to this email, your message will b

[Qgis-user] QGIS airlines: connecting airports with lines ?

[Falk Huettmann]

Hi there,

I have a question, if I may:

at the following website

http://openflights.org/data.html

there are these maps of airlines, connecting airports.

http://openflights.org/demo/openflights-routedb-2048.png

The actual map and code can apparently be bought,
but instead I am looking for a self-made solution (I do not like how people
cash in on a GIS bottleneck).

Would you perhaps know how that map can be done, e.g.
in QGIS or related in an OpenGIS framework or code?

Thanks so much; kind regards
 Falk
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

Re: [Qgis-user] QGIS/R and ISO metadata ?

[Falk Huettmann]

Dear Colleagues,
Thanks indeed; I am very impressed.
You will hear from me next days once I digested these details and URL (new
to me, great).
Thanks again, more soon
  Falk

-Original Message-
From: Blumentrath, Stefan [mailto:stefan.blumentr...@nina.no]
Sent: Sunday, March 12, 2017 1:07 AM
To: Falk Huettmann; qgis-user@lists.osgeo.org
Subject: RE: [Qgis-user] QGIS/R and ISO metadata ?

Hei Falk,

Good that you ask!
Actually, right now there is a great opportunity to contribute to
implementing comprehensive and efficient metadata management in QGIS.

A thorough discussion (https://gitter.im/qgis/metadata) , involving QGIS
developers, metadata experts and interested QGIS users, has led to a long
term plan in this regards:
https://docs.google.com/document/d/1twE8J345Sz1rk1z34672eqlEiL2mJT4bZbuF5oRTCoM/edit#heading=h.j6lg9sa71mq6
(which is not necessarily final)

See also: https://github.com/qgis/QGIS-Enhancement-Proposals/issues/91 and
the other QEPs mentioned in the document above.

We (NINA) work on quite similar things than you do (in an SDM context you
might probably also be interested in:
https://github.com/NaturalHistoryMuseum/ckanext-gbif).

NINA will contribute financially to the development of metadata management
in QGIS, as we see that as an important step for efficient work flows in our
institution (meaning good tools here will save us money in terms of work
time in the long run). Hope many other institutions will join this
initiative!

Kind regards,
Stefan

-Original Message-
From: Qgis-user [mailto:qgis-user-boun...@lists.osgeo.org] On Behalf Of Falk
Huettmann
Sent: lørdag 11. mars 2017 23.34
To: qgis-user@lists.osgeo.org
Subject: [Qgis-user] QGIS/R and ISO metadata ?

Dear Colleagues,

Thanks for your QGIS work; we use it all the time, and in a university.
teaching
and international research & field work setting.
We need more...

I might have asked earlier, but would you know what to do re. ISO compliant
metadata in QGIS ?
On and off, ARCGIS (sorry to mention that name here) had a pretty good
extension and editor on XML metadata for GIS data.

Do you mind to enlighten me for QGIS, R and similar when it comes to this
essential question of data documentation (all else but the Achilles heel) ?

Here some reasons why it matters (URL) and what this is about (citation)

http://www.earth-syst-sci-data-discuss.net/essd-2016-65/

Zuckerberg, B, F. Huettmann and J. Friar (2011). Proper Data Management as a
Scientific Foundation for Reliable Species Distribution Modeling. 
Chapter 3
In: C.A.
Drew, Y. Wiersma and F. Huettmann (eds). Predictive Species and Habitat
Modeling
in Landscape Ecology. Springer, New York. Pp 45-70.

Please keep me posted on this relevant matter as much as possible.

Thanks in advance; kind regards
  Falk

Falk Huettmann PhD, Associate Professor
-EWHALE lab- Biology and Wildlife Dept., Institute of Arctic Biology
419 IRVING I, University of Alaska Fairbanks AK 99775-7000 USA Email
fhuettm...@alaska.edu  Phone 907 474 7882 Fax 907 474 6716
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

[Qgis-user] QGIS/R and ISO metadata ?

[Falk Huettmann]

Dear Colleagues,

Thanks for your QGIS work; we use it all the time, and in a university.
teaching
and international research & field work setting.
We need more...

I might have asked earlier, but would you know what to do re. ISO compliant
metadata
in QGIS ?
On and off, ARCGIS (sorry to mention that name here) had a pretty good
extension and editor on
XML metadata for GIS data.

Do you mind to enlighten me for QGIS, R and similar when it comes to this
essential question
of data documentation (all else but the Achilles heel) ?

Here some reasons why it matters (URL) and what this is about (citation)

http://www.earth-syst-sci-data-discuss.net/essd-2016-65/

Zuckerberg, B, F. Huettmann and J. Friar (2011). Proper Data Management as a
Scientific Foundation for Reliable Species Distribution Modeling. 
Chapter 3
In: C.A.
Drew, Y. Wiersma and F. Huettmann (eds). Predictive Species and Habitat
Modeling
in Landscape Ecology. Springer, New York. Pp 45-70.

Please keep me posted on this relevant matter as much as possible.

Thanks in advance; kind regards
  Falk

Falk Huettmann PhD, Associate Professor
-EWHALE lab- Biology and Wildlife Dept., Institute of Arctic Biology
419 IRVING I, University of Alaska Fairbanks AK 99775-7000 USA
Email fhuettm...@alaska.edu  Phone 907 474 7882 Fax 907 474 6716
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

[Qgis-user] Metadata and databases; thanks RE: Backing up GIS Data

[Falk Huettmann]

Hi there,



Thanks,

I am fully with the notion of back-ups and data management, specifically,

metadata (a topic we pushed for over a decade but it has no good uptake,
still).



While some QGIS users might still try to learn Danish terms (a peculiar
language that is just spoken by some

~60mio people or so; sorry to say it), I sincerely hope the next version of
QGIS is in Chinese instead, and thus serves many billions. OpenSource is
well served then. The EU-centrism ain’t so funny, in GIS, R and beyond.



Equally serious, I do not believe that QGIS, overall, is so powerful on the
actual database side of things.

If possible here, I would highly appreciate to learn specific and powerful
links on HOW QGIS relates and works with databases, and what the underlying
concept, idea and visions are ?

Thanks in advance for that.



In addition, in case you know of latest ISO metadata (XML I assume; I see
virus filter issues in that) approaches to QGIS and tabs and packages I
would die for learning about it for sure, too.

It’s so much needed.



Envision Chinese GIS data all available and documented with metadata open
source for everybody to use…

why not ?



Thanks in advance; very best regards

   Falk Huettmann



Falk Huettmann PhD, Associate Professor

-EWHALE lab- Biology and Wildlife Dept., Institute of Arctic Biology

419 IRVING I, University of Alaska Fairbanks AK 99775-7000 USA

Email fhuettm...@alaska.edu  Phone 907 474 7882 Fax 907 474 6716





*From:* Qgis-user [mailto:qgis-user-boun...@lists.osgeo.org] *On Behalf Of *Bo
Victor Thomsen
*Sent:* Thursday, July 14, 2016 9:04 PM
*To:* qgis-user@lists.osgeo.org
*Subject:* Re: [Qgis-user] Backing up GIS Data



As an old GIS database dog -

   - It's a wise and smart decision to use Postgres/PostGis for storing and
   using spatial data.
   - As for backup: Do *exactly* as Jeff writes :-). "Point in time"
   backups are nice, but not the best backup solution for Postgres databases.
   Jeff's solution is.


Regards

Bo Victor Thomsen
AestasGIS
Denmark










Den 14/07/16 kl. 21:26 skrev Jeff McKenna:

Hi Tyler,

This is a good question, and an important one, and don't feel bad about
posting it here - likely we can all learn from this discussion, as it
definitely involves the whole QGIS community.

I have quite a lot of experience backing up databases, especially
PostgreSQL/PostGIS databases.  I can tell you that it is for sure important
to run "pg_dump" as a daily backup (in addition to your whole server
image/backup) - that pg_dump has saved me and my clients hundreds of times,
and it is very portable and easy to access (as opposed to your whole
image/machine backup).  One very important point (that's I've learned from
experience) when using pg_dump is to *always* use the custom
binary/compressed output format (the "--format=c" commandline switch for
pg_dump).  I've had terrible times with the other output format types,
especially when restoring a database from a Windows server to a Linux
server etc (with hardcoded paths inside the backup).  I live by that
format, swear by it, from experience, moving so many client databases from
one machine to another.

Another mailing list to keep in mind is the PostGIS mailing list, where
these backup topics also pop up from time to time - and discussions are
more geo-related, so are very helpful, than just the generic PostgreSQL
mailing list.

So, definitely implement an additional backup process using pg_dump (you
can experiment restoring it through the "pg_restore" command), you won't
regret the effort spent.

Happy QGIS-ing,

-jeff
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: http://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-user

[Qgis-user] style sheet help, thanks

[Falk Huettmann]

Hi,

in QGIS Vienna 2.8.2 I cannot get the style sheets to save and to load.

I comprehend the general concept,
but it's not functioning (=nothing to save,
nothing to load, names I gave are nowhere to find. Not for qml nor for sld).

Would somebody be able to help me, and for how to track details to make it
work?

(I would like to repeat a classification scheme on a continuous column for
many shapefiles using points without a pen/outline and a smaller size)


Thanks so much
   Falk Huettmann
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/qgis-user

Re: [Qgis-user] Local Government for QGIS

[Falk Huettmann]

Dear all,

thanks,
I find this is a very essential discussion to have, and with
QGIS, GDAL/R etc at its core and solution.

Much can be said, and should be said and changed,
but here a few points for a start:

-mapping relates to land, health and water management questions; many of
these are widely unresolved nor do many people really want it to be
resolved even.

-mapping is, and remains, a highly strategic and military topic.

-mapping affects economic growth and our neoliberal economy policy.
Software is directly embedded in that; now all driven by online developments
and its drivers.

-mapping and its tools and data are part of democracy.


Thus, a (tried) control of mapping, its data, and its tools, must come of
no big surprise. It's a heavily vested subject.
(one can add easily remote sensing perspectives in that discussion, and one
really should).

These things are not new, apply globally, and are part of any good
Geography textbook really.
I would go that far and put it as a major topic for Climate Change!

So I think the current status of GIS  governments and its inertia can
widely be derived from there.
We have much experience in that, world-wide (happy to share if somebody
wants to know; just ask...).

What about a good set of GIS and Remote Sensing ETHICS ?

Yes, I find it's time things change for the better.
Keep me posted please.

 Very best and thanks
 Falk Huettmann



On Thu, Jun 11, 2015 at 12:28 PM, Steve G stevenlgol...@gmail.com wrote:

 I am not sure this is the correct forum for a start to this discussion, but
 I've been pondering this for a while and interested what others think.  I
 work for local government in the U.S. and when people generally talk about
 GIS there is no doubt an automatic association with the ESRI ArcGIS
 platform.  And beyond GIS itself, the dominance that ESRI has is even more
 pronounced given the fact that many cities have implemented other related
 systems (permitting, computer aided dispatch, etc) that are identified
 business partners with ESRI.  Furthermore, the GIS Local Government track
 that ESRI developed has evolved to offer an turnkey approach for local
 government self-service to establish a robust geodatabase (Local Government
 Information Model), maps, apps, web services, etc.  This extends a COTS
 approach for local governments to establish, develop, and maintain a fairly
 complete GIS.  In my opinion, pure genius...because for a lot of small
 cities/governments with limited staff and budget, the turnkey approach is
 very appealing.  For city bureaucrats thinking about implementing/extending
 GIS, what they might think as little $$$ and you get all of this?
 Awesome...here's my money.

 HOWEVER, this approach has its drawbacks.  Long-term license/use costs,
 vendor lock-in, continuous waiting for someone at the company to fix
 somethingwell, the list goes on (just read any blog post supporting
 open
 source/FOSS).

 So, with the evolution of QGIS as a prevailing replacement/alternative for
 the other product, is anyone thinking about building more of a turnkey
 approach (database, maps, apps, web services, etc) geared to local
 governments?  I like the direction of the OpenGeo platform (and others)
 trying to provide the whole software stack, but still if a small local
 government wants to have a full fledged interactive GIS, it might seem like
 a lot of work to develop and maintain.

 I am interested in other thoughts...perhaps this belongs on a blog post
 somewhere more independent, but perhaps this can be a place to begin.

 Steve G.



 --
 View this message in context:
 http://osgeo-org.1560.x6.nabble.com/Local-Government-for-QGIS-tp5210489.html
 Sent from the Quantum GIS - User mailing list archive at Nabble.com.
 ___
 Qgis-user mailing list
 Qgis-user@lists.osgeo.org
 http://lists.osgeo.org/mailman/listinfo/qgis-user

___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/qgis-user

[Qgis-user] QGIS: great at sea...(teaching research in the field)

[Falk Huettmann]

Dear colleagues,

I just wanted to quickly report back on a question I posed here app.
9 months ago re. the use of OpenGIS (QGIS) on a ship and teaching vessel:

In summary, I can only say the best how this worked out on the ship and
with students!

The software had no installation problems, was not clumsy, dealt with a
variety of lab set-ups and hardware + OSs, and it provided for a brilliant
and steady approach to mapping, GPS linkage, use of online data, and
oceans/terrestrial applications while traveling across several seas and
cultures. A diversity of students and skills can be catered.
Cannot be better!

It opened up many student's minds, and in comparison to just Google Earth.

I found, QGIS made for a wonderful example of 'inquiry-based' learning in
the real world.

So in conclusion, I can recommend it highly for (ocean) field schools and
field lab settings.
Over time, I would be delighted to hear from other people and their
experiences re. QGIS use and teaching etc, too.

Thanks; very best
 Falk

Falk Huettmann PhD, Associate Professor
-EWHALE lab-
Biology  Wildlife Dept, Inst. of Arctic Biology
University of Alaska Fairbanks
Fairbanks Alaska 99775 USA
Email fhuettm...@alaska.edu  Tel +1 907 474 7882
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/qgis-user

Re: [Qgis-user] QGIS from External drive ?

[Falk Huettmann]

Wow, thanks so much.
That would be a big help.
(We need it on a ship, and installations there are weird).
So a plain PC laptop run via an external drive would be the way to go.


Thanks once more; kindly

F.



*From:* luca forestello [mailto:fra...@gmail.com]
*Sent:* Monday, August 11, 2014 1:25 AM
*To:* qgis-user@lists.osgeo.org; fhuettm...@alaska.edu
*Subject:* Re: [Qgis-user] QGIS from External drive ?



On Windows,
you can try this version of Qgis 2.4 that not requires installation and
does not require administrative privileges.

http://webgis.arpa.piemonte.it/pub/QGIS_portable_Chugiak_24_32bit.zip

You need to download the file qgis_portable.zip, unzip the file (for
example, C:\Program Files\Qgis_portable, USB or external HD  should be the
same thing).
At the end of this operation, which can take several minutes, in the folder
qgis_portable, you will find a new folder QGIS and a new file
qgis.bat (MS-DOS Batch File).
To start Qgis 2.4 simply double-click on the file qgis.bat.

Kind regards
Luca Forestello
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/qgis-user

[Qgis-user] QGIS from External drive ?

[Falk Huettmann]

Dear Colleagues,



I have a quick question (I was not able to achieve the below despite
trying):

Could I run QGIS from an external drive (like a plug-in drive) ?

I would need that instead of a regular c:drive installation on a PC.

How is that done ?

And if that is not possible, what would be the alternatives ?



(we face the situation that in a lab the PCs are not allowed to download
and install anything etc etc.

I know that OpenOffice can run from a USB stick fine, and I was told that
QGIS can do similar, yes ?)



Thanks so much for any feedback.

Kind regards

   F.



Falk Huettmann PhD, Associate Professor

-EWHALE lab- Biology and Wildlife Dept., Institute of Arctic Biology

419 IRVING I, University of Alaska Fairbanks AK 99775-7000 USA

Email fhuettm...@alaska.edu  Phone 907 474 7882 Fax 907 474 6716
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/qgis-user

Re: [Qgis-user] Vector to Raster Conversion, was :[Euclidean Distance grid creation problem]

[Falk Huettmann]

Ah, thanks indeed Alex.

Yes, for the 'grey' map legend, setting the Min to Max values (you find
the max in Histogram tab) and Stretch them out makes it work (lower left
setting).

One ought to know...(I have similar legend display issues with ArcGIS
sometimes)

Wow, thanks; very best
   F.

PS. We are now looking for a tool to intersect the grids with points
(drill-down, to grab
the underlying point layer values from grids. Can that be done in qgis too
? We use extract in R,
or intersect in Hawths tools (GME; works usually best), or Extract Values
to Points in ArcGIS). Thanks indeed for any pointers.

-Original Message-
From: Alex Mandel [mailto:tech_...@wildintellect.com]
Sent: Tuesday, June 04, 2013 1:12 PM
To: Falk Huettmann
Cc: qgis-user
Subject: Re: [Qgis-user] Vector to Raster Conversion, was :[Euclidean
Distance grid creation problem]

I ran your data, it worked fine for me. Yes initially it all looks 1
color. After going into the Properties. choosing to use Custom Min/Max
values, Selecting to Load from Actual, and stretching min/max. I can see
the data no problem.

I can see why sampling randomly with the info tool won't work, since you
need to click info exactly where a river line occurs.

http://www.pasteall.org/pic/52841

Thanks,
Alex

On 06/04/2013 01:37 PM, Alex Mandel wrote:
 Ok, now we're getting somewhere. There error is specifically with the
 GDAL rasterize tool (has no direct link to a euclidean distance tool).

 Can you please post the GDAL command from the bottom box of that tool?

 Thanks,
 Alex

 On 06/04/2013 01:14 PM, Falk Huettmann wrote:
 thanks, re. Euclidean Distance problem,

 we use the following point layer (shapefile attached) and with the
 GDAL plugin.

 We click on Raster, Rasterize (but get a grey canvas; all values in
 the legend show the same. Using line data has the same effect).
 We cannot proceed from that.

  From there we wanted to get a Euclidean Distance and using Raster,
 Analyse, Distance.

 We got stuck in this for over 3 weeks now (paper on Open Source GIS)
 and wonder how to proceed next and for good progress.

 Thanks so much for any insights.

 Very best from Alaska
 F.





 On Mon, Jun 3, 2013 at 9:21 PM, Alex Mandel
 tech_...@wildintellect.comwrote:

 On 06/03/2013 10:02 PM, Falk Huettmann wrote:

 Dear all,

 greetings;
 we are still stuck with creating a Euclidean Distance grid in QGIS
 based on point data (shapefile, projected in lat lon and with an ID
 of 1).

 I am aware of the steps shown online, but these create us just a
 grey canvas.
 (we tried different pixel and extent settings too)

 We are grateful for  any input (if not resolved, we will probably
 move to R then and other options).

 Thanks indeed for any input; more later
Falk Huettmann



 Grey pixels do not mean no data. Did you check the values of random
 pixels with the Info tool?

 Normally in the raster properties you have ask QGIS to calculate the
 range of values, and stretch min/max in order to actually see what
 you expect, or put in a custom color ramp.

 Also what tutorial did you follow and which tool did you use to
 calculate the distance grid.

 Thanks,
 Alex




 ___
 Qgis-user mailing list
 Qgis-user@lists.osgeo.org
 http://lists.osgeo.org/mailman/listinfo/qgis-user
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/qgis-user

Re: [Qgis-user] Vector to Raster Conversion, was :[Euclidean Distance grid creation problem]

[Falk Huettmann]

...cool, we shall try that one.

Will be grand; THANKS.
Yours kindly
F.

Falk Huettmann PhD, Associate Professor
-EWHALE lab- Biology and Wildlife Dept., Institute of Arctic Biology
419 IRVING I, University of Alaska Fairbanks AK 99775-7000 USA
Email fhuettm...@alaska.edu  Phone 907 474 7882 Fax 907 474 6716

-Original Message-
From: Ing. Juan M. Bernales [mailto:jm_berna...@hotmail.com]
Sent: Tuesday, June 04, 2013 7:19 PM
To: Falk Huettmann
Cc: QGIS
Subject: Re: [Qgis-user] Vector to Raster Conversion, was :[Euclidean
Distance grid creation problem]

The Point Sampling Tool is the plugin you are looking for PS. We are now
looking for a tool to intersect the grids with points
(drill-down, to grab the underlying point layer values from grids. Can that
be done in qgis too ? We use extract in R, or intersect in Hawths tools
(GME; works usually best), or Extract Values to Points in
ArcGIS). Thanks indeed for any pointers.

-Mensaje original-
From: Falk Huettmann
Sent: Tuesday, June 04, 2013 4:43 PM
To: t...@wildintellect.com
Cc: qgis-user ; jeffrey_ev...@tnc.org ; Michael Lindgren ; 云
Subject: Re: [Qgis-user] Vector to Raster Conversion, was :[Euclidean
Distance grid creation problem]

Ah, thanks indeed Alex.

Yes, for the 'grey' map legend, setting the Min to Max values (you find the
max in Histogram tab) and Stretch them out makes it work (lower left
setting).

One ought to know...(I have similar legend display issues with ArcGIS
sometimes)

Wow, thanks; very best
   F.

PS. We are now looking for a tool to intersect the grids with points
(drill-down, to grab the underlying point layer values from grids. Can that
be done in qgis too ? We use extract in R, or intersect in Hawths tools
(GME; works usually best), or Extract Values to Points in ArcGIS). Thanks
indeed for any pointers.

-Original Message-
From: Alex Mandel [mailto:tech_...@wildintellect.com]
Sent: Tuesday, June 04, 2013 1:12 PM
To: Falk Huettmann
Cc: qgis-user
Subject: Re: [Qgis-user] Vector to Raster Conversion, was :[Euclidean
Distance grid creation problem]

I ran your data, it worked fine for me. Yes initially it all looks 1 color.
After going into the Properties. choosing to use Custom Min/Max values,
Selecting to Load from Actual, and stretching min/max. I can see the data no
problem.

I can see why sampling randomly with the info tool won't work, since you
need to click info exactly where a river line occurs.

http://www.pasteall.org/pic/52841

Thanks,
Alex

On 06/04/2013 01:37 PM, Alex Mandel wrote:
 Ok, now we're getting somewhere. There error is specifically with the
 GDAL rasterize tool (has no direct link to a euclidean distance tool).

 Can you please post the GDAL command from the bottom box of that tool?

 Thanks,
 Alex

 On 06/04/2013 01:14 PM, Falk Huettmann wrote:
 thanks, re. Euclidean Distance problem,

 we use the following point layer (shapefile attached) and with the
 GDAL plugin.

 We click on Raster, Rasterize (but get a grey canvas; all values in
 the legend show the same. Using line data has the same effect).
 We cannot proceed from that.

  From there we wanted to get a Euclidean Distance and using Raster,
 Analyse, Distance.

 We got stuck in this for over 3 weeks now (paper on Open Source GIS)
 and wonder how to proceed next and for good progress.

 Thanks so much for any insights.

 Very best from Alaska
 F.





 On Mon, Jun 3, 2013 at 9:21 PM, Alex Mandel
 tech_...@wildintellect.comwrote:

 On 06/03/2013 10:02 PM, Falk Huettmann wrote:

 Dear all,

 greetings;
 we are still stuck with creating a Euclidean Distance grid in QGIS
 based on point data (shapefile, projected in lat lon and with an ID
 of 1).

 I am aware of the steps shown online, but these create us just a
 grey canvas.
 (we tried different pixel and extent settings too)

 We are grateful for  any input (if not resolved, we will probably
 move to R then and other options).

 Thanks indeed for any input; more later
Falk Huettmann



 Grey pixels do not mean no data. Did you check the values of random
 pixels with the Info tool?

 Normally in the raster properties you have ask QGIS to calculate the
 range of values, and stretch min/max in order to actually see what
 you expect, or put in a custom color ramp.

 Also what tutorial did you follow and which tool did you use to
 calculate the distance grid.

 Thanks,
 Alex




 ___
 Qgis-user mailing list
 Qgis-user@lists.osgeo.org
 http://lists.osgeo.org/mailman/listinfo/qgis-user
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/qgis-user
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/qgis-user

[Qgis-user] Euclidean Distance grid creation problem

[Falk Huettmann]

Dear all,

greetings;
we are still stuck with creating a Euclidean Distance grid in QGIS
based on point data (shapefile, projected in lat lon and with an ID of 1).

I am aware of the steps shown online, but these create us just a grey
canvas.
(we tried different pixel and extent settings too)

We are grateful for  any input (if not resolved, we will probably move to R
then and other options).

Thanks indeed for any input; more later
 Falk Huettmann
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/qgis-user

[Qgis-user] rasterize points and distance problem ?

[Falk Huettmann]

Dear Colleagues,

I have a question in qgis (PC) we cannot resolve:

we have a point data set (shapefile projected) and want to rasterize
it for a distance estimate.

But in qgis, and doing all steps as requested, just brings us a plain grey
canvas/grid (large minus values).
We cannot see any points within, and for the next step (= distance measure
from these points).

This should be trivial, but we lost now over  a week because of this, and
we see no good
solution anywhere (presumably it is due to extent and pixel scale but we
tried changing
settings there and had no luck. We also changed the projections without
success. We added a column for the 1 id).

Any help would be highly appreciated; THANKS.
(we can send you the point data, or would be happy learning from a dataset
that actually works, too).

Thanks so much in advance for any pointers

Falk Huettmann  Co.

PS I assume doing point overlays (=drill down, intersect, extraction) is
easy, but for any input there  we would be helpful also.
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/qgis-user