Hey,
There is an ESRI code (ESRI:102318
<http://spatialreference.org/ref/esri/102318/>) corresponding to the
requested projection... However, I doubt CRS will take an ESRI code
(Roger ?).
Jonathan, have a look at the rgdal and sp packages help pages for the
"How To" in CRS()
Best regards
Alex
Le 24/08/2010 17:58, Roger Bivand a écrit :
> On Tue, 24 Aug 2010, Alexandre Villers wrote:
>
>> Hello,
>>
>> Have a look at spTransform (in rgdal package) and the EPSG code of
>> the desired projection (this is to me the easiest way not to mess
>> with digits and various copy errors that can be made while writing
>> the projection properties) at www.spatialreference.org
>>
>> then, you just have to do something like this
>>
>> library(rgdal)
>>
>> data<-read.table ("mydata.txt", h=T, sep=",") #your original dataset
>> coordinates(data)<-~ X + Y # where X and Y stand for the name of your
>> lat/lon columns
>> proj4string(data)<-CRS("+init=epsg:4326") #if your coordinates are
>> in WGS84
>> data.proj<-spTransfrom(data,
>> CRS("+init=epsg:the.correct.epsg.number.of.your.projection")
>
> Looks like:
>
> http://spatialreference.org/ref/epsg/32118/
>
> but has some different parameters. Search on "New York" in this site
> for alternatives.
>
> Roger
>
>>
>> HTH
>>
>> Alex
>>
>>
>> Le 24/08/2010 16:51, Jonathan Marc Bearak a écrit :
>>> Hi,
>>>
>>> I'm new to GIS and have been trying to convert latitude and
>>> longitude to/from state plane coordinates.
>>>
>>> I've tried using the project() program from the proj4 library to
>>> convert lat/lng to FIPS 3104 (New York State Long Island).
>>>
>>> No matter how I go about this, however, the coordinates come out
>>> wrong. E.g.,
>>> "+proj=lcc +lat_1=40.66666666666666
>>> +lat_2=41.03333333333333 +lat_0=40.16666666666666 +lon_0=-74
>>> +x_0=300000 +y_0=0 +units=ft +no_defs +datum=NAD83",
>>> "+proj=lcc +a=6378137 +es=.0066943800229 +lon_0=-74
>>> +lat_1=41d2 +lat_2=40d40 +lat_0=40d10 +x_0=300000 +y_0=0 +units=ft
>>> +no_defs +datum=NAD83",
>>>
>>> E.g., if I try the inverse, to convert 1062791, 209606.6 to lat/lng,
>>> project() prints: 43.04762 -76.89626. The correct coordinates,
>>> however, are: 40.7416495 -073.7165681.
>>>
>>> I've been reading the mailing lists and searching Google and R
>>> project PDFs and manual pages without any luck for an embarrassingly
>>> long number of hours without any luck.
>>>
>>> Thanks for any help.
>>>
>>> Best,
>>> Jonathan
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>>> R-sig-Geo@stat.math.ethz.ch
>>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>>
>>
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