[R-sig-Geo] Problems with writeGDAL (gridded function)

[Pierre Roudier]

Sorry for posting again,

Reading through the raster reference manual, I just realised you can
actually use the raster package internal function for writing rasters,
writeRaster() :

library(raster)
data(drg) # Loading some sample data
class(drg) # drg is a "RasterLayer" object
writeRaster(drg, "bar.tif") # No class conversion needed

This is more straightforward, and it's using GDAL as well for most formats,

Pierre

2010/8/9 Pierre Roudier <pierre.roudier at gmail.com>:
> Hi Ana,
>
> Your post is missing some details, like your sessionInfo() output, and
> the way you are reading your data.
>
> From what I understand, you are using the (excellent) raster package
> to read your data, that's why the class of your data is "RasterLayer".
>
> The writeGDAL() function from the rgdal package is not able to cope
> with that class AFAIK. You have to translate your object from the
> RasterLayer class to an sp class (typically SpatialPixelsDataFrame for
> raster data), as follows:
>
> library(raster)
> library(rgdal)
> data(drg) # Loading some sample data
> class(drg) # drg is a "RasterLayer" object
> writeGDAL(drg, "foo.tif", drivername="GTiff") # You get an error
> because writeGDAL can't  deal with RasterLayer objects
> drg.sp <- as(drg, "SpatialPixelsDataFrame") # Converting the
> RasterLayer object to a SpatialPixelsDataFrame object
> class(drg.sp)
> writeGDAL(drg.sp, "foo.tif", drivername="GTiff") # This should work
>
> Hope this help,
>
> Pierre
>
> 2010/8/9 rras terr <rrasterr at gmail.com>:
>> I all,
>>
>> I am having problems in exporting data using writeGDAL & create2GDAL:
>>
>> Error in function (classes, fdef, mtable)  :
>> unable to find an inherited method for function "gridded", for signature
>> "RasterLayer"
>> Calls: writeGDAL -> create2GDAL -> stopifnot -> gridded -> <Anonymous>
>>
>> --
>> rgdal version: 0.6-28
>> --
>>
>> Any suggestion?
>>
>> Thanks in advance,
>> Ana
>>
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>>
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>