UTM to longlat
Its all quite simple I think (i.e. "hope"). Have
you used spTransform(rdgal)?
## here I have a file from a local group delivered
## in UTM format that I transformed OK to long-lat.
library(rgdal) # for map projection support; automatically loads sp
## transform internal measurements from UTM to long lat format
longlat_sp <- spTransform(UTM_format_sp, CRS("+init=epsg:4326"))
sapply(slot(longlat_sp, "polygons"), function(x) slot(x, "ID"))
> showMethods("spTransform")
Function: spTransform (package rgdal)
x="SpatialGridDataFrame", CRSobj="CRS"
x="SpatialLines", CRSobj="CRS"
x="SpatialLinesDataFrame", CRSobj="CRS"
x="SpatialPixelsDataFrame", CRSobj="CRS"
x="SpatialPoints", CRSobj="CRS"
x="SpatialPointsDataFrame", CRSobj="CRS"
x="SpatialPolygons", CRSobj="CRS"
x="SpatialPolygonsDataFrame", CRSobj="CRS"
Hope this helps,
Jim Burke
Renaud Lancelot wrote:
Thank you Edzer. I was hoping there was a simpler solution, but it's still fairly simple. Renaud 2009/5/7 Edzer Pebesma <edzer.pebesma at uni-muenster.de>
Yes, but you will not like that call. In R (package sp), each spatial data set can only have one single projection. I'd suggest, in pseudo-code - import the data into a data.frame - for each UTM zone do: select the locations set their CRS reproject to long/lat - cbind the locations to a single data structure - convert back to data.frame if needed. -- Edzer Pebesma Institute for Geoinformatics (ifgi), University of M?nster Weseler Stra?e 253, 48151 M?nster, Germany. Phone: +49 251 8333081, Fax: +49 251 8339763 http://ifgi.uni-muenster.de/ http://www.springer.com/978-0-387-78170-9 e.pebesma at wwu.de Renaud Lancelot wrote:
Dear all,
I have a big dataset (> 200,000 lines) of georeferenced locations
where the coordinates are given in UTM, spanning over several zones.
Is is possible to convert all the UTM coordinates into longlat WGS84
with a single call ?
Renaud
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