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spTransform results

2 messages · Sylvia Churcher, Roger Bivand

Original
Sylvia Churcher
# 
Hello all,

Being a new and cautious user of the rgdal library I am having trouble
confirming that my results are correct.

transforming vectors with long and lat values to easting and northing in zone
16, datum=NAD83

I'll obviously omit the entire vectors, but include the first 2 lines for
reference

*coords.x1 is long (vector name:  lake.info$Longitude_W);
coords.x2 is lat (vector name:  lake.info$Latitude_N)

SpatialPoints:
      coords.x1 coords.x2
 [1,]     89.59     46.02
 [2,]     89.67     46.12

Using the code:
SP_grd <- SpatialPoints(cbind(lake.info$Longitude_W, lake.info$Latitude_N),
proj4string=CRS("+proj=longlat +datum=NAD83"))

SP_grd1 <- spTransform(SP_grd, CRS("+proj=utm +zone=16 +datum=NAD83"))

My result is:
SpatialPoints:
      coords.x1 coords.x2
 [1,] -83121879 -53374442
 [2,] -82861240 -54157633

==> My main problem is that I'm not able to check that these resulting values
are correct and that I haven't made an error in my code.  The I've tried using
online converters and the results are not matching.  My lat and long points are
all for Wisconsin, USA (specifically zone 16T in NAD83).

Thank you any and all for your help.
Roger Bivand
#
On Tue, 20 May 2008, Sylvia Churcher wrote:

            

      
      
      
    

        
^^^^^

These look like Sinkiang to me - or a more recent translitteration. GE 
goes to Western China too if you type 89.59E 46.02N; 89.59W is near Vilas 
WI. If they are degrees W, they ought to be negative.

Hope this helps,

Roger