OK, I got it, it works, thank you so much!!! 2010/8/31 J Luis <[email protected]>
> Carmelo, > > In GMT with GDAL support that is trivial to do using the grdtrack program. > > Joaquim Luis > > > Hello everybody, > first of all my apologies cause I'm a newbie with this stuff... > > I'm trying to build a function able to extract altitude from latitude and > longitude as parameters. > Something like that: *double MyElevation(double lat, double lon)* > * > * > I'm using Dted level 0 to get the elevation (I've already read this post: > http://www.osgeo.org/pipermail/gdal-dev/2010-February/023457.html ) > But I got lost... :( > > *GDALAllRegister(); > * > *pointerToDataSet=(GDALDataset*) GDALOpen("n30.dt0", GA_ReadOnly);* > * * > *double data[6];* > *double longitude, latitude;* > * > * > *pointerToDataSet->GetGeoTransform(data);* > * > * > *longitude=???;* > *latitude=???;* > * * > *double x = (longitude - pippo[0]) / pippo[1];* > *double y = (latitude - pippo[3]) / pippo[5];* > * * > *GDALRasterBand* pointerToBand;* > * * > *pointerToBand=pointerToDataSet->GetRasterBand(1);* > * * > *float *elevation;* > * * > *pointerToDataSet->RasterIO(?,?, ... , ?);* > *pointerToBand->RasterIO(?,?, ... , ?);* > > > I supposed I had to store elevation data into the buffer I created, I > mean the float pointer. > I got confused among these: > - the file *.dt0 > - longitude and latitude > - parameters for RasterIO() > > Every tips will be very appreciated, thanks a lot for your patience, > Regards, > Carmelo > > > _______________________________________________ > gdal-dev mailing list > [email protected]http://lists.osgeo.org/mailman/listinfo/gdal-dev > > >
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