Re: [Qgis-user] Relations capabilities

[Neumann, Andreas]

Hi Brent, 

The relations are a complicated topic and are being worked on. As you
have discovered, they are also still a bit limited in what you can do
with them until now. But I hope that is will change in the future. 

I can summarize a bit what you can do with them now: 

- embed linked/filtered tables in forms (I recommend you use it with the
drag and drop forms and put them in separate tabs) 

- you can add/delete features in related tables 

- for n:m you can also link/unlink records in related tables 

- for n:m there is a new mode now in 2.14 where you can hide the
in-between link table 

- in print composer in atlas context you can use it as a table source to
create data-sheets 

There may be more what you can do. I don't claim that my list is
complete. And of course different organizations have different
needs/requirements/ideas what they want to do with the relations. 

Now what you want to do (select/filter features in a related table based
on a selection in a related table) is not yet possible. I invite you to
specify exactly what you want and join the relations effort to improve
what you can do with relations in future QGIS versions. 

My organization has plans to have aggregate functions implemented on
related tables - things like count, sum, mean, min, max, concatenate,
etc. - to be used in tables or in the print composer (atlas context). 

Greetings, 

Andreas 

On 2016-02-24 02:16, Brent Wood wrote:

> Firstly, thanks to those who already helped me with this. 
> 
> I have established a relation between non-spatial catch records in a postgis 
> table and a table of station information (linked via foreign key). 
> 
> If I click on a station with the info tool, I can see the various catch 
> records from that station - so the relation is working. 
> 
> But that seems to be it. If I filter on the species in the catch, that only 
> applies to the catch data showing up when I select a station - it does NOT 
> hide stations where that species was not caught. I cannot change symbology 
> based on a relation, I cannot select features based on a relation - all I can 
> do is view the records - and with 70 fields in the station layer, the catch 
> records are just a small window at the bottom of the form. 
> 
> It seems that to be useful I need to create the view or table in the database 
> & access this with QGIS - whioch has issues for users without create access 
> in the database - which is most of them. 
> 
> Is work on this area (relations) of QGIS actively ongoing, or should I look 
> for non-QGIS approaches? 
> 
> Thanks, 
> 
> Brent Wood 
> 
> ___
> 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 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

Re: [Qgis-user] Relations capabilities

[Bernhard Ströbl]

Hi Brent,

not sure if I uttered that before, so (if I did) my apologies for 
repeating myself. If you are entirely on PostgreSQL you may try my 
Plugin DataDrivenInputMask [1]. If you have properly defined foreign 
keys you can

1) see the species caught in one station in a list [2]
2) search for (and thus select) stations where certain species have been 
caught

I assume
a) a station table with pk field station_pk
b) a species table with pk field species_pk
c) a relation table with a combined pk = station_pk + species_pk, where 
station_pk is a fk on station.station_pk and species_pk is a fk on 
species.species_pk


Regarding symbology you may filter your station layer like that:
station_pk IN (SELECT station_pk FROM relation_table where species_pk = 
some_value)
You would need to load your station layer several times and filter each 
of them on one (or several) species for symbolization.


Another way would be to use PostgreSQL's crosstab extension and create a 
view for symbolization only which would list all the species in one 
dataset like that

station_pk, geom, station_name, species_1, species_2,...,species_n
You could then classify on the combinations

Bernhard

[1] http://plugins.qgis.org/plugins/DataDrivenInputMask/
[2] 
https://github.com/bstroebl/DataDrivenInputMask/wiki/Widgets-for-n-2-m-Relations


Am 24.02.2016 um 02:16 schrieb Brent Wood:

Firstly, thanks to those who already helped me with this.
I have established a relation between non-spatial catch records in a postgis 
table and a table of station information (linked via foreign key).
If I click on a station with the info tool, I can see the various catch records 
from that station - so the relation is working.
But that seems to be it. If I filter on the species in the catch, that only 
applies to the catch data showing up when I select a station - it does NOT hide 
stations where that species was not caught. I cannot change symbology based on 
a relation, I cannot select features based on a relation - all I can do is view 
the records - and with 70 fields in the station layer, the catch records are 
just a small window at the bottom of the form.
It seems that to be useful I need to create the view or table in the database & 
access this with QGIS - whioch has issues for users without create access in the 
database - which is most of them.
Is work on this area (relations) of QGIS actively ongoing, or should I look for 
non-QGIS approaches?
Thanks,
   Brent Wood




__ Information from ESET Mail Security, version of virus signature 
database 13076 (20160223) __

The message was checked by ESET Mail Security.
http://www.eset.com



Firstly, thanks to those who already helped me with this.

I have established a relation between non-spatial catch records in a
postgis table and a table of station information (linked via foreign key).

If I click on a station with the info tool, I can see the various catch
records from that station - so the relation is working.

But that seems to be it. If I filter on the species in the catch, that
only applies to the catch data showing up when I select a station - it
does NOT hide stations where that species was not caught. I cannot
change symbology based on a relation, I cannot select features based on
a relation - all I can do is view the records - and with 70 fields in
the station layer, the catch records are just a small window at the
bottom of the form.

It seems that to be useful I need to create the view or table in the
database & access this with QGIS - whioch has issues for users without
create access in the database - which is most of them.

Is work on this area (relations) of QGIS actively ongoing, or should I
look for non-QGIS approaches?

Thanks,

   Brent Wood




__ Information from ESET Mail Security, version of virus
signature database 13076 (20160223) __

The message was checked by ESET Mail Security.
http://www.eset.com


___
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





__ Information from ESET Mail Security, version of virus signature 
database 13077 (20160224) __

The message was checked by ESET Mail Security.
http://www.eset.com


___
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

Re: [QGIS-it-user] Viewshed analysis Plugin e ultime versioni

[Paolo Cavallini]

Il 23/02/2016 23:10, terry cusanno ha scritto:
> 
>> Se serve a te, puoi:
>> * offrirti di pagare per il lavoro dello sviluppatore originale
>> * pagare qualcun altro, che fara' l'aggiunta necessaria
>> * imparare a farlo tu.
>> Ovviamente l'ultima opzione e' la preferibile :)
> 
> Anche io pensavo la stessa cosa! ;)
> Bàvediamo!

se ti interessa l'ultima opzione, chiedi pure qui, c'e' chi ti puo' dare
suggerimenti. Dovrebbe essere banale.
Saluti.

-- 
Paolo Cavallini - www.faunalia.eu
QGIS & PostGIS courses: http://www.faunalia.eu/training.html
___
QGIS-it-user mailing list
QGIS-it-user@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/qgis-it-user

[Qgis-user] Relations capabilities

[Brent Wood]

Firstly, thanks to those who already helped me with this.
I have established a relation between non-spatial catch records in a postgis 
table and a table of station information (linked via foreign key).
If I click on a station with the info tool, I can see the various catch records 
from that station - so the relation is working.
But that seems to be it. If I filter on the species in the catch, that only 
applies to the catch data showing up when I select a station - it does NOT hide 
stations where that species was not caught. I cannot change symbology based on 
a relation, I cannot select features based on a relation - all I can do is view 
the records - and with 70 fields in the station layer, the catch records are 
just a small window at the bottom of the form.
It seems that to be useful I need to create the view or table in the database & 
access this with QGIS - whioch has issues for users without create access in 
the database - which is most of them.
Is work on this area (relations) of QGIS actively ongoing, or should I look for 
non-QGIS approaches?
Thanks,
  Brent Wood

___
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] Clipped tif files - black sea, white land.

[Steve Steve]

I am sure that I have missed something but I am trying to clip raster files 
(eg. bio9.tif) which have data on land but are blank beyond the coastal margins.

Clipping these in Qgis ('Raster', 'Extraction', 'Clipper') results in a tif 
file (e.g. 'bio9_clip.tif') that iseers black over the sea and white over the 
land and has apparently lost all the data that was in the original file.

Anyone know what causes this?

Cheers,
Steve
  ___
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-it-user] Lecos - edge length

[Luca Puglisi]

Buongiorno,

sto utilizzando per la prima volta questo plug-in per la misurazione di 
parametri tipici della landscape ecology. Forse qualcuno di voi puo' 
aiutarmi a capire una cosa: nella misura della lunghezza del margine di 
un poligono di cui a me interessa la parte inclusa entro un buffer 
circolare, direi che viene incluso anche il margine stesso del buffer.
Tanto per spiegare meglio, se il buffer cade tutto all'interno di un 
unico poligono piu' grande, la lunghezza del margine dovrebbe essere 
pari a 0, piuttosto che la circonferenza del buffer che invece direi che 
e' il risultato (leggermente falsato perche' il calcolo avviene su raster).

Se e' effettivamente cosi', esiste un sistema per ovviare?

grazie, un saluto a tutti
Luca Puglisi


---
Questa e-mail è stata controllata per individuare virus con Avast antivirus.
https://www.avast.com/antivirus

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

[QGIS-it-user] Volete fare qualcosa di utile?

[Paolo Cavallini]

Aggiungete qualche test per i moduli di processing. Questi verranno
fatti girare automaticamente, quindi garantirete a tutti che i risultati
rimangano sempre corretti, in tutte le prossime versioni di QGIS. Fatelo
per gli algoritimi che conoscete meglio, di cui vi servano risultati certi.
Vedi qui di seguito per le istruzioni. Chi si cimenta, scriva in lista,
cosi' aiutera' anche gli altri a partire.
Saluti, e grazie anticipate.
===

It is very easy to expand this suite. Test definitions are written in
the form of yaml. Templates for this definitions can be created from the
processing history. There are some possibilities to fine-tune the
comparison (e.g. skip fields, allow values to be compared with an
epsilon, match a result file with a series of regular expressions...)
which have been added more recently. At the moment it runs tests for
some qgis algorithms and gdal algorithms.

If you have 5 minutes to spare today, please help and add a test!

More information can be found in our blog [1] and the readme [2].

Thanks a lot,
Matthias

https://github.com/qgis/QGIS/blob/master/python/plugins/processing/tests/README.md
-- 
Paolo Cavallini - www.faunalia.eu
QGIS & PostGIS courses: http://www.faunalia.eu/training.html
___
QGIS-it-user mailing list
QGIS-it-user@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/qgis-it-user

Re: [QGIS-it-user] Viewshed analysis Plugin e ultime versioni di QGIS

[Paolo Cavallini]

Il 23/02/2016 00:26, terry cusanno ha scritto:
> Come da consiglio di Paolo, ho aperto un ticket (assegnandolo
> direttamente all'autore del plugin) equesta è stata la risposta:
> " Aggiornato da Zoran Čučković  1
> giorno  fa
> 
>   * *Priorità* modificata da /Normal/ a /Low/
> 
>  
> Hello!
> I get this question quite often! The viewshed plugin does not support
> special characters, such as é, ç, ñ, č, đ, ž etc. (not only in file
> names, but also in folder names). I'm not planinng to fiddle whith that
> problem..."

Grazie.
Ragionevole che, se non gli serve, non metta il suo tempo per sistemarlo.
Se serve a te, puoi:
* offrirti di pagare per il lavoro dello sviluppatore originale
* pagare qualcun altro, che fara' l'aggiunta necessaria
* imparare a farlo tu.
Ovviamente l'ultima opzione e' la preferibile :)
Saluti, e grazie. Ogni piccola cosa come questa contribuisce a
migliorare il software di tutti.
-- 
Paolo Cavallini - www.faunalia.eu
QGIS & PostGIS courses: http://www.faunalia.eu/training.html
___
QGIS-it-user mailing list
QGIS-it-user@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/qgis-it-user

Re: [Qgis-user] Elevation model from xyz data? GIS <- archaeology

[Micha Silver]

  
  

  
The simple
  way to interpolate a set of point elevations to a DEM is with
  the gdal_grid tool. It appears in the QGIS menu:
  Raster->Analysis->Grid(Interpolation). 
  You need to choose the interpolation method, which column
contains the Z values, and the final grid resolution that
you want.
   HTH
  



-- Original Message --
  Subject: [Qgis-user] Elevation model from xyz data? GIS <-
  archaeology
  Date: Mon, 22 Feb 2016 23:54:27 -0800 (PST)
  To: Qgis-user
  From: Absalon


On 23/02/2016 09:54, Absalon wrote:


  Hello!

I need to create a digital elevation model for the visualization of an old
landscape based on archaeological data. Usually I'm working with AutoCAD,
but this software has no capabilities for DEM. My option is now QGIS!

My data is an xyz-file. I managed to import this file into QGIS. Nice green
points!

My CAD trained brain now thinks, this layer has to be marked and a tool for
making digital elevation models has to be started. But this does not work.
It seems to me, QGIS wants to load a rasterlayer. I have got no rasterlayer,
just my points... 

Can anyone help me? GIS workflow is very confusing to me...



--
View this message in context: http://osgeo-org.1560.x6.nabble.com/Elevation-model-from-xyz-data-GIS-archaeology-tp5252164.html
Sent from the Quantum GIS - User mailing list archive at Nabble.com.
___
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
This mail was received via Mail-SeCure System.



  Micha Silver
Arava Drainage Authority
+972-523-665918

  

___
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] Elevation model from xyz data? GIS <- archaeology

[Absalon]

Hello!

I need to create a digital elevation model for the visualization of an old
landscape based on archaeological data. Usually I'm working with AutoCAD,
but this software has no capabilities for DEM. My option is now QGIS!

My data is an xyz-file. I managed to import this file into QGIS. Nice green
points!

My CAD trained brain now thinks, this layer has to be marked and a tool for
making digital elevation models has to be started. But this does not work.
It seems to me, QGIS wants to load a rasterlayer. I have got no rasterlayer,
just my points... 

Can anyone help me? GIS workflow is very confusing to me...



--
View this message in context: 
http://osgeo-org.1560.x6.nabble.com/Elevation-model-from-xyz-data-GIS-archaeology-tp5252164.html
Sent from the Quantum GIS - User mailing list archive at Nabble.com.
___
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