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I have a CSV-list of coordinates that I know are coordinates in Gauß-Krüger (Transverse Mercator) and I want to transform them to UTM in R with GDAL.

I read the csv in, separated the columns, added the original source proj4string while creating a SpatialPoints object. Then I tried to transform the data with ogr2ogr but always get the error message:

"Error in as.character.default(new("SpatialPoints", coords = c(3480702.68, : no method for coercing this S4 class to a vector"

library(gdalUtils)
library(rgdal)
library(rgeos)
library(sp)

ExamplePoints <- read.csv2("C:/Users/Desktop/Test.csv", header = TRUE,  
  dec = ",")

points_SRC <- ExamplePoints[3:4]

ExamplePoints_SRC <- SpatialPoints(points_SRC,   
  proj4string=CRS("+proj=tmerc +lat_0=0 +lon_0=9 +k=1 +x_0=3500000 +y_0=0 
  +ellps=bessel +towgs84=598.1,73.7,418.2,0.202,0.045,-2.455,6.7 +units=m 
  +no_defs"))

Transform_test <- ogr2ogr(src_datasource_name = ExamplePoints_SRC,      
  dst_datasource_name = "C:/Users/Desktop/Test.shp", f = "ESRI 
  Shapefile", t_srs = "+proj=tmerc +lat_0=0 +lon_0=9 +k=0.9996 
  +x_0=32500000 +y_0=0 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m 
  +no_defs", s_srs = "+proj=tmerc +lat_0=0 +lon_0=9 +k=1 +x_0=3500000 
  +y_0=0 +ellps=bessel +towgs84=598.1,73.7,418.2,0.202,0.045,-2.455,6.7  
  +units=m +no_defs", a_srs= "EPSG:4647")

I do not understand the error message. What kind of input does ogr2ogr expect instead? I could not get an answer to this until now unforunately.

Did anyone experience a similar error or does understand what GDAL wants instead?

This is how the CSV file looks like in the editor (the decimal separator is ',' and the column separator is ';' : 

point number;source CRS;x;y;target CRS;x;y
1;31467;3480702,68;5380141,08;4647;32480635,05;5378428,48
2;31467;3516958,39;5423993,28;4647;32516876,30;5422263,10
3;31467;3533028,71;5384162,09;4647;32532940,13;5382447,91
4;31467;3504712,87;5405841,58;4647;32504635,69;5404118,72

This is the table of coordinates before the making a SpatialPoint object out of it: This is the table of coordinates before the making a SpatialPoint object out of it

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  • 1
    Can you include the content of the Test.csv file (a few lines) instead of the image of the table? – Gabriel De Luca Feb 9 at 18:42
  • I added them in the question. I hope that is visible. – Li12 Feb 10 at 12:49
  • Why don't you just use spTransform instead? – Jeffrey Evans Feb 10 at 13:59
  • Because with spTransform I did not see a possibility to assign a specific defintion of the grid, if I am not mistaken. I would like to conduct that in the next step though for comparison reasons (... +units=m +nadgrids"PATH TO NTV2 GRID") – Li12 Feb 11 at 9:58
1

In the documentation for ogr2ogr:

Usage:

     ogr2ogr(src_datasource_name, dst_datasource_name, layer, f, append,

where:

src_datasource_name: Character. Input vector file.
dst_datasource_name: Character. Output vector file.

these arguments are Character. Input vector file. - they are NOT spatial R objects. They would be, for example, paths to shapefiles.

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