[R-sig-Geo] ecw for rgdal package

Alex Mandel tech_dev at wildintellect.com
Wed Dec 23 08:09:54 CET 2009


Roger Bivand wrote:
> On Mon, 21 Dec 2009, Alexandre VILLERS wrote:
> 
>> Good afternoon,
>>
>> I was wondering if the reading and creating of ecw files was planned
>> for the rgdal library. I suppose it is a bit tricky to include this
>> function because of the need for the ECW SDK library from ER mapper...
> 
> Correct, we cannot distribute this library from CRAN. If you need this
> driver, you have to provide it yourself, on Windows using the
> instructions for the alternative build approach in:
> 
> file.show(system.file("README.windows", package="rgdal"))
> 
> You will have to improvise a little, as - for example - building R
> packages from source is easier now than it was in 2007.
> 
> Hope this helps,
> 
> Roger
> 

I believe the ECW dll for GDAL is available in the OSGEO4W package, and
my understanding of it is that as long as the dll is present on your
gdal path for the gdal install that rgdal is using it should work.
http://trac.osgeo.org/osgeo4w/

I can't speak for ECW but I do know for MrSID there's been clarification
on several occasions that it is ok to distribute the built binary.

Alex



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