[R-sig-Geo] function to convert to/from U.S. State Plane Coordinates?
Roger Bivand
Roger.Bivand at nhh.no
Tue Sep 17 08:56:40 CEST 2013
On Tue, 17 Sep 2013, Waichler, Scott R wrote:
> My system is Redhat, RHEL5.
The package does document all of these requirements:
file.show(system.file("README", package="rgdal"))
or:
https://r-forge.r-project.org/scm/viewvc.php/pkg/inst/README?view=markup&root=rgdal
or read the inst/README file from the source package tarball. Note that
the Fedora/RHEL case is covered specifically.
Nothing about projections is ever simple, nobody should assume that it is.
The assumption is very anachronistic, as clear standards have only been
available recently (say < 20 years, even < 10 years for GNSS/GPS), and
most maps are older; mapping agencies value continuity, and use their
legacy definitions, which vary greatly from place to place, and are often
not well defined.
Note also the link on the Spatial Task View to:
http://spatialreference.org/
as a resource for investigating which incantation may match your data. As
has been mentioned, State Plane contains hundreds of candidate
definitions, depending among other things on the part of the state
concerned and the datum in use at the time the data were created.
Searching this website for "Washington" - your location state - gives 18
hits in EPSG, and only you can know which is appropriate.
Hope this clarifies,
Roger
>
>> str(pnw)
> List of 4
> $ x : num [1:893] -117 -117 -117 -117 -117 ...
> $ y : num [1:893] 46 46 45.9 45.9 45.9 ...
> $ range: num [1:4] -125 -111 42 49
> $ names: chr [1:7] "idaho" "oregon" "washington:san juan island" "washington:lopez island" ...
> - attr(*, "class")= chr "map"
>
> So, it sounds like there is extra proj4 stuff that I need to install beyond the base installation I already did, which also enabled installation of rgdal?
>
> Scott
>
>> -----Original Message-----
>> From: Hodgess, Erin [mailto:HodgessE at uhd.edu]
>> Sent: Monday, September 16, 2013 5:12 PM
>> To: Waichler, Scott R; Rob Robinson
>> Cc: r-sig-geo at r-project.org
>> Subject: RE: [R-sig-Geo] function to convert to/from U.S. State Plane
>> Coordinates?
>>
>> I think that you need to download some proj4 stuff. If you're on Ubuntu,
>> go to the Ubuntu package search page and you'll find it.
>>
>> Also, what is the str(pnw.spc) please?
>>
>> Thanks,
>> Erin
>>
>>
>> -----Original Message-----
>> From: Waichler, Scott R [mailto:Scott.Waichler at pnnl.gov]
>> Sent: Monday, September 16, 2013 7:10 PM
>> To: Hodgess, Erin; Rob Robinson
>> Cc: r-sig-geo at r-project.org
>> Subject: RE: [R-sig-Geo] function to convert to/from U.S. State Plane
>> Coordinates?
>>
>> I am working in Linux.
>>
>> I clicked on the ESRI:102749 option on the spatialreference.org website
>> that Rob referred to, and got a spec that looks like it should work inside
>> CRS(), but something seems to be amiss.
>>
>>> library(rgdal)
>>> pnw.spc <- spTransform(pnw, CRS = CRS("+proj=lcc
>>> +lat_1=45.83333333333334 +lat_2=47.33333333333334
>>> +lat_0=45.33333333333334 +lon_0=-120.5 +x_0=500000.0000000002 +y_0=0
>>> +ellps=GRS80 +datum=NAD83 +to_meter=0.3048006096012192 +no_defs"))
>> Error in spTransform(pnw, CRS = CRS("+proj=lcc +lat_1=45.83333333333334
>> +lat_2=47.33333333333334 +lat_0=45.33333333333334 +lon_0=-120.5
>> +x_0=500000.0000000002 +y_0=0 +ellps=GRS80 +datum=NAD83
>> +to_meter=0.3048006096012192 +no_defs")) :
>> load package rgdal for spTransform methods
>>
>>>
>>> Are you in Windows or a Linux type computer, please?
>>>
>>>
>>>
>>> -----Original Message-----
>>> From: r-sig-geo-bounces at r-project.org [mailto:r-sig-geo-bounces at r-
>>> project.org] On Behalf Of Waichler, Scott R
>>> Sent: Monday, September 16, 2013 6:49 PM
>>> To: Rob Robinson
>>> Cc: r-sig-geo at r-project.org
>>> Subject: Re: [R-sig-Geo] function to convert to/from U.S. State Plane
>>> Coordinates?
>>>
>>> Ok, now I know about the existence of EPSG codes, but apparently my
>>> rgdal installation can't find the list of them? Do I need to find a
>>> certain file in my system's PROJ4 installation, then tell that to rgdal?
>>>
>>>> library(maps)
>>>> library(rgdal)
>>>> pnw <- map('state', region = c('washington', 'oregon', 'idaho'),
>>>> plot=F) epsg <- make_EPSG()
>>> Error in make_EPSG() : Error opening epsg file
>>>> pnw.spc <- spTransform(pnw, CRS=CRS("+init=epsg:102749"))
>>> Error in spTransform(pnw, CRS = CRS("+init=epsg:102749")) :
>>> error in evaluating the argument 'CRSobj' in selecting a method for
>>> function 'spTransform': Error in CRS("+init=epsg:102749") : no system
>>> list, errno: 13
>>>
>>> --Scott
>>>
>>>> try following the instructions
>>>> here http://www.gpsmeter.com/index.php?page=faq14 to find an epsg
>>>> code then something along the lines of spTransform(data,
>>>> CRS=CRS("+init=epsg:xxx")) should work?
>>>>
>>>> On 17 September 2013 00:09, Waichler, Scott R
>>>> <Scott.Waichler at pnnl.gov>
>>>> wrote:
>>>> Erin, thanks, I'm getting closer. Rgdal's projInfo() lists UTM,
>>>> which I believe is closely related to the State Plane Coordinate
>>>> system, but I still don't see a direct transformation to SPC in R.
>>>> --Scott Waichler
>>>>
>>>>
>>>>> Could you mean spTransform from rgdal, please?
>>>>>
>>>>> Hi, Does an R function exist to convert to and from the State
>>>>> Plane Coordinates system used in the U.S.? My search with Rseek
>>>>> was
>>>> fruitless.
>>>
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>>> R-sig-Geo at r-project.org
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>
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--
Roger Bivand
Department of Economics, NHH Norwegian School of Economics,
Helleveien 30, N-5045 Bergen, Norway.
voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: Roger.Bivand at nhh.no
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