gzfile gives a connection, which readGDAL does not support - you need an actual dataset name that GDAL can understand (not necessarily just a file path btw).
I think you will have to extract the tif with shell/system calls to gzip or similar - what OS are you using? Rtools provides a handy gzip that could be used if your system doesn't already have it (e.g. Windows). There are virtual drivers in GDAL for reading from compressed files (similar to the R gzfile connection mechanism), but it will depend on the installation of GDAL that you have with rgdal: http://trac.osgeo.org/gdal/wiki/UserDocs/ReadInZip http://osgeo-org.1803224.n2.nabble.com/Support-for-reading-GDAL-datasets-in-compressed-archives-gz-and-zip-td2035285.html It's not available on my system as far as I know ( or I'm not using it correctly) - if it were avaible in the GDAL used to build rgdal it should allow readGDAL to read from the "/vsigzip/path....gz" string. Cheers, Mike. On Fri, Jun 4, 2010 at 10:40 PM, Alexandre VILLERS <alexandre.vill...@cebc.cnrs.fr> wrote: > Good afternoon, > > I know this not the most appropriate place to post this message but I hope > that some of you have already been confronted to the same problem. > I have a lot of NDVI tiff files that have been compressed with gzip > (filename such as 81jul15a.n07-VIg_data.tif.gz ) and that I need to > geoprocess with R. I would like to unzip the tif from within R but was not > able to properly understand how to connect to the gz file and unzip it with > this with function gzfile. > Anybody with some lines of codes hanging that would save my afternoon (and > help me understand how the connection works) ? > > Best regards and thanks for any help. > > Alex > > -- > Alexandre Villers > PhD. > AgriPop > Centre d'Etudes Biologiques de Chizé-CNRS UPR1934 > 79360 Beauvoir sur Niort > > Phone +33 (0)5 49 09 96 13 > Fax +33 (0)5 49 09 65 26 > > > > > __________ Information from ESET Mail Security, version of virus signature > database 5171 (20100604) __________ > > The message was checked by ESET Mail Security. > http://www.eset.com > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo