Re: [R-sig-Geo] Help with latlong to UTM conversion when UTM zones are different

2015-03-28 Thread Barry Rowlingson
On 27 Mar 2015 23:50, "Robert J. Hijmans"  wrote:
>
> Are these really reasonable reasons? I do not think so, given that the
> question had nothing to do with map navigation and the person asking
> appears to live in the UK.

??? How did you figure that out? He gave some phone numbers that had
Botswana country codes and a southern hemisphere utm zone code! Elementary
my dear Robert!

But yes, as I said, if there's a local standard use it. To find the local
standard, buy a paper map and read the projection info! I would never use
UTM in the uk when epsg:27700 is our standard.

> Moreover, other projections have, or can
> have, their units in meters as well (or feet or miles or whatever you
> might fancy). UTM indeed appears to be an unfortunate default that
> deserves some pushback.

I see utm as a last resort rather than a default. However finding a better
coordinate system in the maze of epsg codes can lead to people using the
wrong thing, and unless you span several zones, utm is never that wrong...

> Robert
>
> On Fri, Mar 27, 2015 at 2:28 PM, Michael Sumner 
wrote:
> > They are reasonable reasons, but traversing zones is a pain, you should
see
> > if using one or the other is sufficient. I would check carefully the
> > distances you get against ellipsoidal calculations.
> >
> > Cheers, Mike
> >
> > On Sat, 28 Mar 2015 07:30 Andrew Duff  wrote:
> >
> >> A number of field folks prefer UTM because
> >>
> >> -it matches legacy paper USGS quad map series traditionally used for
field
> >> navigation
> >> -units are in meters and can be used to gauge field distances from a
> >> coordinate readout
> >>
> >>
> >>
> >> > On Mar 27, 2015, at 10:48 AM, Michael Sumner 
wrote:
> >> >
> >> > There is no good natural reason to use UTM, it mistifies me why our
> >> > community tolerates this bizarre default. I always use a local
equal-area
> >> > projection unless some other compromise dictates a different choice.
> >> > Cheers, Mike
> >> >
> >> > On Fri, 27 Mar 2015 21:28 Barry Rowlingson <
b.rowling...@lancaster.ac.uk
> >> >
> >> > wrote:
> >> >
> >> >> If you have lat-long data that crosses two UTM zones then its
> >> >> generally okay to just pick *one* and transform all the points to
> >> >> that. Use the one that has the most points in. Basically use the UTM
> >> >> zones as guidelines to pick one UTM zone coordinate system. Unless
> >> >> your data spans several zones and you want quite high accuracy of
> >> >> distance measurements. Some points bleeding over into an adjacent
zone
> >> >> are no problem.
> >> >>
> >> >> All projections are approximations to the earth's spheroid, so
points
> >> >> that are within a single UTM zone have some distortion in their
> >> >> distance or angle relationships. Transforming points that are within
> >> >> an adjacent UTM zone is just an extension of that distortion. You
can
> >> >> compute the precise distance error if you want for the furthest
points
> >> >> by comparing with the geodesic distance.
> >> >>
> >> >> Alternatively you might find there is a coordinate system that spans
> >> >> your dataset nicely - often when a country or an island or a region
> >> >> crosses UTM zones there is an official coordinate system defined
that
> >> >> is used by the authorities there.
> >> >>
> >> >> Also alternatively, there's nothing to stop you defining a
transverse
> >> >> mercator system based on the centre of your data.
> >> >>
> >> >> Barry
> >> >>
> >> >>
> >> >>
> >> >> On Fri, Mar 27, 2015 at 7:44 AM, moses selebatso <
> >> selebat...@yahoo.co.uk>
> >> >> wrote:
> >> >>> Hello
> >> >>> I have animal movement data that I have converted from Lat/Long to
UTM,
> >> >> unfortunately the data falls in two UTM zones (34S and 35S). For
some
> >> >> reason R cannot display both of them in the same window (the 35S
data is
> >> >> way off the expected location).
> >> >>> The question is how do I convert the data such that R can correctly
> >> read
> >> >> it?
> >> >>> Moses SELEBATSO
> >> >>>
> >> >>> (+267) 318 5219 (H) (+267) 716 393 70 (C)
> >> >>>  (+267) 738 393 70 (C
> >> >>>[[alternative HTML version deleted]]
> >> >>>
> >> >>> ___
> >> >>> R-sig-Geo mailing list
> >> >>> R-sig-Geo@r-project.org
> >> >>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> >> >>
> >> >> ___
> >> >> R-sig-Geo mailing list
> >> >> R-sig-Geo@r-project.org
> >> >> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> >> >
> >> >[[alternative HTML version deleted]]
> >> >
> >> > ___
> >> > R-sig-Geo mailing list
> >> > R-sig-Geo@r-project.org
> >> > https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> >>
> >
> > [[alternative HTML version deleted]]
> >
> > ___
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> > R-sig-Geo@r-project.org
> > https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>
> ___

Re: [R-sig-Geo] Help with latlong to UTM conversion when UTM zones are different

2015-03-27 Thread Robert J. Hijmans
Are these really reasonable reasons? I do not think so, given that the
question had nothing to do with map navigation and the person asking
appears to live in the UK. Moreover, other projections have, or can
have, their units in meters as well (or feet or miles or whatever you
might fancy). UTM indeed appears to be an unfortunate default that
deserves some pushback.
Robert

On Fri, Mar 27, 2015 at 2:28 PM, Michael Sumner  wrote:
> They are reasonable reasons, but traversing zones is a pain, you should see
> if using one or the other is sufficient. I would check carefully the
> distances you get against ellipsoidal calculations.
>
> Cheers, Mike
>
> On Sat, 28 Mar 2015 07:30 Andrew Duff  wrote:
>
>> A number of field folks prefer UTM because
>>
>> -it matches legacy paper USGS quad map series traditionally used for field
>> navigation
>> -units are in meters and can be used to gauge field distances from a
>> coordinate readout
>>
>>
>>
>> > On Mar 27, 2015, at 10:48 AM, Michael Sumner  wrote:
>> >
>> > There is no good natural reason to use UTM, it mistifies me why our
>> > community tolerates this bizarre default. I always use a local equal-area
>> > projection unless some other compromise dictates a different choice.
>> > Cheers, Mike
>> >
>> > On Fri, 27 Mar 2015 21:28 Barry Rowlingson > >
>> > wrote:
>> >
>> >> If you have lat-long data that crosses two UTM zones then its
>> >> generally okay to just pick *one* and transform all the points to
>> >> that. Use the one that has the most points in. Basically use the UTM
>> >> zones as guidelines to pick one UTM zone coordinate system. Unless
>> >> your data spans several zones and you want quite high accuracy of
>> >> distance measurements. Some points bleeding over into an adjacent zone
>> >> are no problem.
>> >>
>> >> All projections are approximations to the earth's spheroid, so points
>> >> that are within a single UTM zone have some distortion in their
>> >> distance or angle relationships. Transforming points that are within
>> >> an adjacent UTM zone is just an extension of that distortion. You can
>> >> compute the precise distance error if you want for the furthest points
>> >> by comparing with the geodesic distance.
>> >>
>> >> Alternatively you might find there is a coordinate system that spans
>> >> your dataset nicely - often when a country or an island or a region
>> >> crosses UTM zones there is an official coordinate system defined that
>> >> is used by the authorities there.
>> >>
>> >> Also alternatively, there's nothing to stop you defining a transverse
>> >> mercator system based on the centre of your data.
>> >>
>> >> Barry
>> >>
>> >>
>> >>
>> >> On Fri, Mar 27, 2015 at 7:44 AM, moses selebatso <
>> selebat...@yahoo.co.uk>
>> >> wrote:
>> >>> Hello
>> >>> I have animal movement data that I have converted from Lat/Long to UTM,
>> >> unfortunately the data falls in two UTM zones (34S and 35S). For some
>> >> reason R cannot display both of them in the same window (the 35S data is
>> >> way off the expected location).
>> >>> The question is how do I convert the data such that R can correctly
>> read
>> >> it?
>> >>> Moses SELEBATSO
>> >>>
>> >>> (+267) 318 5219 (H) (+267) 716 393 70 (C)
>> >>>  (+267) 738 393 70 (C
>> >>>[[alternative HTML version deleted]]
>> >>>
>> >>> ___
>> >>> R-sig-Geo mailing list
>> >>> R-sig-Geo@r-project.org
>> >>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>> >>
>> >> ___
>> >> R-sig-Geo mailing list
>> >> R-sig-Geo@r-project.org
>> >> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>> >
>> >[[alternative HTML version deleted]]
>> >
>> > ___
>> > R-sig-Geo mailing list
>> > R-sig-Geo@r-project.org
>> > https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>
>
> [[alternative HTML version deleted]]
>
> ___
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Re: [R-sig-Geo] Help with latlong to UTM conversion when UTM zones are different

2015-03-27 Thread Michael Sumner
They are reasonable reasons, but traversing zones is a pain, you should see
if using one or the other is sufficient. I would check carefully the
distances you get against ellipsoidal calculations.

Cheers, Mike

On Sat, 28 Mar 2015 07:30 Andrew Duff  wrote:

> A number of field folks prefer UTM because
>
> -it matches legacy paper USGS quad map series traditionally used for field
> navigation
> -units are in meters and can be used to gauge field distances from a
> coordinate readout
>
>
>
> > On Mar 27, 2015, at 10:48 AM, Michael Sumner  wrote:
> >
> > There is no good natural reason to use UTM, it mistifies me why our
> > community tolerates this bizarre default. I always use a local equal-area
> > projection unless some other compromise dictates a different choice.
> > Cheers, Mike
> >
> > On Fri, 27 Mar 2015 21:28 Barry Rowlingson  >
> > wrote:
> >
> >> If you have lat-long data that crosses two UTM zones then its
> >> generally okay to just pick *one* and transform all the points to
> >> that. Use the one that has the most points in. Basically use the UTM
> >> zones as guidelines to pick one UTM zone coordinate system. Unless
> >> your data spans several zones and you want quite high accuracy of
> >> distance measurements. Some points bleeding over into an adjacent zone
> >> are no problem.
> >>
> >> All projections are approximations to the earth's spheroid, so points
> >> that are within a single UTM zone have some distortion in their
> >> distance or angle relationships. Transforming points that are within
> >> an adjacent UTM zone is just an extension of that distortion. You can
> >> compute the precise distance error if you want for the furthest points
> >> by comparing with the geodesic distance.
> >>
> >> Alternatively you might find there is a coordinate system that spans
> >> your dataset nicely - often when a country or an island or a region
> >> crosses UTM zones there is an official coordinate system defined that
> >> is used by the authorities there.
> >>
> >> Also alternatively, there's nothing to stop you defining a transverse
> >> mercator system based on the centre of your data.
> >>
> >> Barry
> >>
> >>
> >>
> >> On Fri, Mar 27, 2015 at 7:44 AM, moses selebatso <
> selebat...@yahoo.co.uk>
> >> wrote:
> >>> Hello
> >>> I have animal movement data that I have converted from Lat/Long to UTM,
> >> unfortunately the data falls in two UTM zones (34S and 35S). For some
> >> reason R cannot display both of them in the same window (the 35S data is
> >> way off the expected location).
> >>> The question is how do I convert the data such that R can correctly
> read
> >> it?
> >>> Moses SELEBATSO
> >>>
> >>> (+267) 318 5219 (H) (+267) 716 393 70 (C)
> >>>  (+267) 738 393 70 (C
> >>>[[alternative HTML version deleted]]
> >>>
> >>> ___
> >>> R-sig-Geo mailing list
> >>> R-sig-Geo@r-project.org
> >>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> >>
> >> ___
> >> R-sig-Geo mailing list
> >> R-sig-Geo@r-project.org
> >> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> >
> >[[alternative HTML version deleted]]
> >
> > ___
> > R-sig-Geo mailing list
> > R-sig-Geo@r-project.org
> > https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>

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Re: [R-sig-Geo] Help with latlong to UTM conversion when UTM zones are different

2015-03-27 Thread Andrew Duff
A number of field folks prefer UTM because 

-it matches legacy paper USGS quad map series traditionally used for field 
navigation
-units are in meters and can be used to gauge field distances from a coordinate 
readout 



> On Mar 27, 2015, at 10:48 AM, Michael Sumner  wrote:
> 
> There is no good natural reason to use UTM, it mistifies me why our
> community tolerates this bizarre default. I always use a local equal-area
> projection unless some other compromise dictates a different choice.
> Cheers, Mike
> 
> On Fri, 27 Mar 2015 21:28 Barry Rowlingson 
> wrote:
> 
>> If you have lat-long data that crosses two UTM zones then its
>> generally okay to just pick *one* and transform all the points to
>> that. Use the one that has the most points in. Basically use the UTM
>> zones as guidelines to pick one UTM zone coordinate system. Unless
>> your data spans several zones and you want quite high accuracy of
>> distance measurements. Some points bleeding over into an adjacent zone
>> are no problem.
>> 
>> All projections are approximations to the earth's spheroid, so points
>> that are within a single UTM zone have some distortion in their
>> distance or angle relationships. Transforming points that are within
>> an adjacent UTM zone is just an extension of that distortion. You can
>> compute the precise distance error if you want for the furthest points
>> by comparing with the geodesic distance.
>> 
>> Alternatively you might find there is a coordinate system that spans
>> your dataset nicely - often when a country or an island or a region
>> crosses UTM zones there is an official coordinate system defined that
>> is used by the authorities there.
>> 
>> Also alternatively, there's nothing to stop you defining a transverse
>> mercator system based on the centre of your data.
>> 
>> Barry
>> 
>> 
>> 
>> On Fri, Mar 27, 2015 at 7:44 AM, moses selebatso 
>> wrote:
>>> Hello
>>> I have animal movement data that I have converted from Lat/Long to UTM,
>> unfortunately the data falls in two UTM zones (34S and 35S). For some
>> reason R cannot display both of them in the same window (the 35S data is
>> way off the expected location).
>>> The question is how do I convert the data such that R can correctly read
>> it?
>>> Moses SELEBATSO
>>> 
>>> (+267) 318 5219 (H) (+267) 716 393 70 (C)
>>>  (+267) 738 393 70 (C
>>>[[alternative HTML version deleted]]
>>> 
>>> ___
>>> R-sig-Geo mailing list
>>> R-sig-Geo@r-project.org
>>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>> 
>> ___
>> R-sig-Geo mailing list
>> R-sig-Geo@r-project.org
>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> 
>[[alternative HTML version deleted]]
> 
> ___
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> R-sig-Geo@r-project.org
> https://stat.ethz.ch/mailman/listinfo/r-sig-geo

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Re: [R-sig-Geo] Help with latlong to UTM conversion when UTM zones are different

2015-03-27 Thread Michael Sumner
There is no good natural reason to use UTM, it mistifies me why our
community tolerates this bizarre default. I always use a local equal-area
projection unless some other compromise dictates a different choice.
Cheers, Mike

On Fri, 27 Mar 2015 21:28 Barry Rowlingson 
wrote:

> If you have lat-long data that crosses two UTM zones then its
> generally okay to just pick *one* and transform all the points to
> that. Use the one that has the most points in. Basically use the UTM
> zones as guidelines to pick one UTM zone coordinate system. Unless
> your data spans several zones and you want quite high accuracy of
> distance measurements. Some points bleeding over into an adjacent zone
> are no problem.
>
> All projections are approximations to the earth's spheroid, so points
> that are within a single UTM zone have some distortion in their
> distance or angle relationships. Transforming points that are within
> an adjacent UTM zone is just an extension of that distortion. You can
> compute the precise distance error if you want for the furthest points
> by comparing with the geodesic distance.
>
> Alternatively you might find there is a coordinate system that spans
> your dataset nicely - often when a country or an island or a region
> crosses UTM zones there is an official coordinate system defined that
> is used by the authorities there.
>
> Also alternatively, there's nothing to stop you defining a transverse
> mercator system based on the centre of your data.
>
> Barry
>
>
>
> On Fri, Mar 27, 2015 at 7:44 AM, moses selebatso 
> wrote:
> >  Hello
> > I have animal movement data that I have converted from Lat/Long to UTM,
> unfortunately the data falls in two UTM zones (34S and 35S). For some
> reason R cannot display both of them in the same window (the 35S data is
> way off the expected location).
> > The question is how do I convert the data such that R can correctly read
> it?
> > Moses SELEBATSO
> >
> > (+267) 318 5219 (H) (+267) 716 393 70 (C)
> >   (+267) 738 393 70 (C
> > [[alternative HTML version deleted]]
> >
> > ___
> > R-sig-Geo mailing list
> > R-sig-Geo@r-project.org
> > https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>
> ___
> R-sig-Geo mailing list
> R-sig-Geo@r-project.org
> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>

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Re: [R-sig-Geo] Help with latlong to UTM conversion when UTM zones are different

2015-03-27 Thread Barry Rowlingson
If you have lat-long data that crosses two UTM zones then its
generally okay to just pick *one* and transform all the points to
that. Use the one that has the most points in. Basically use the UTM
zones as guidelines to pick one UTM zone coordinate system. Unless
your data spans several zones and you want quite high accuracy of
distance measurements. Some points bleeding over into an adjacent zone
are no problem.

All projections are approximations to the earth's spheroid, so points
that are within a single UTM zone have some distortion in their
distance or angle relationships. Transforming points that are within
an adjacent UTM zone is just an extension of that distortion. You can
compute the precise distance error if you want for the furthest points
by comparing with the geodesic distance.

Alternatively you might find there is a coordinate system that spans
your dataset nicely - often when a country or an island or a region
crosses UTM zones there is an official coordinate system defined that
is used by the authorities there.

Also alternatively, there's nothing to stop you defining a transverse
mercator system based on the centre of your data.

Barry



On Fri, Mar 27, 2015 at 7:44 AM, moses selebatso  wrote:
>  Hello
> I have animal movement data that I have converted from Lat/Long to UTM, 
> unfortunately the data falls in two UTM zones (34S and 35S). For some reason 
> R cannot display both of them in the same window (the 35S data is way off the 
> expected location).
> The question is how do I convert the data such that R can correctly read it?
> Moses SELEBATSO
>
> (+267) 318 5219 (H) (+267) 716 393 70 (C)
>   (+267) 738 393 70 (C
> [[alternative HTML version deleted]]
>
> ___
> R-sig-Geo mailing list
> R-sig-Geo@r-project.org
> https://stat.ethz.ch/mailman/listinfo/r-sig-geo

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[R-sig-Geo] Help with latlong to UTM conversion when UTM zones are different

2015-03-27 Thread moses selebatso
 Hello
I have animal movement data that I have converted from Lat/Long to UTM, 
unfortunately the data falls in two UTM zones (34S and 35S). For some reason R 
cannot display both of them in the same window (the 35S data is way off the 
expected location).
The question is how do I convert the data such that R can correctly read it?
Moses SELEBATSO

(+267) 318 5219 (H) (+267) 716 393 70 (C)
  (+267) 738 393 70 (C
[[alternative HTML version deleted]]

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