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rgislatitude-longitudergdal

Convert latitude/longitude to state plane coordinates


I've got a dataset with latitude and longitude which I'd like to convert to the state plane coordinates for Illinois East, using EPSG 2790 (http://spatialreference.org/ref/epsg/2790/) or maybe ESRI 102672 (http://spatialreference.org/ref/esri/102672/).

This has definitely been asked before; my code is based on the answers here ("Non Finite Transformation Detected" in spTransform in rgdal R Package and http://r-sig-geo.2731867.n2.nabble.com/Converting-State-Plane-Coordinates-td5457204.html).

But for some reason I can't get it to work:

library(rgdal)
library(sp)
data = data.frame(long=c(41.20,40.05), lat=c(-86.14,-88.15))
coordinates(data) <- ~ long + lat
proj4string(data) <- CRS("+init=epsg:4326") # latitude/longitude
data.proj <- spTransform(data, CRS("+init=epsg:2790")) # illinois east

Gives:

non finite transformation detected:
  long    lat               
 41.20 -86.14    Inf    Inf 
Error in spTransform(data, CRS("+init=epsg:2790")) : failure in points 1
In addition: Warning message:
In spTransform(data, CRS("+init=epsg:2790")) :
  2 projected point(s) not finite

Solution

  • When you set the coordinates for your data, you have to set the latitude before the longitude.

    In other words, change:

    coordinates(data) <- ~ long + lat

    to

    coordinates(data) <- ~ lat+long

    And it should work.

    library(rgdal)
    library(sp)
    data = data.frame(long=c(41.20,40.05), lat=c(-86.14,-88.15))
    coordinates(data) <- ~ lat+long
    proj4string(data) <- CRS("+init=epsg:4326")
    data.proj <- spTransform(data, CRS("+init=epsg:2790"))
    data.proj
    

    Gave me this output:

    SpatialPoints:
              lat     long
    [1,] 483979.0 505572.6
    [2,] 315643.7 375568.0
    Coordinate Reference System (CRS) arguments: +init=epsg:2790 +proj=tmerc
    +lat_0=36.66666666666666 +lon_0=-88.33333333333333 +k=0.9999749999999999 +x_0=300000
    +y_0=0 +ellps=GRS80 +units=m +no_defs