OK guys, I got it, very helpful! Thank you so much 2010/9/6 Even Rouault <[email protected]>
> Yes , what you see is expected. > > The prototype of RasterIO() is : > > RasterIO( flag, x, y, width, height, buffer, buffer_width, buffer_height, > gdal_type, pixel_offset, line_offset) > > so that means that you ask the extraction of the window [x, x + with-1] x > [y, > y + height -1] to be stored in a buffer_width x buffer_height buffer. > > so if you set x to be non-null, you cannot ask for the full XSize to be > read, > the maximum value for width is XSize - x. > > See > http://gdal.org/classGDALRasterBand.html#5497e8d29e743ee9177202cb3f61c3c7 > for the full reference. > > Le lundi 06 septembre 2010 17:25:31, Carmelo Terrasi a écrit : > > Hello everybody, > > I'm trying to figure out how to get elevation from a .dem file. > > > > I opened the file: > > ... > > pointerToDataSet=(GDALDataset*) GDALOpen("myFile.dem", GA_ReadOnly); > > ... > > > > > > So I caught a grid as a 371x371 matrix, but I can read only the first > line, > > so the first 371 elevations... the error is: *...Access window out of > range > > in RasterIO()...* > > > > I mean If I put coordinates like (*0*, *somethingelse*) where 0<* > > somethingelse<*370: > > ... > > pointerToBand->RasterIO( GF_Read, 0, *somethingelse*, nXSize, 1, > elevation, > > nXSize, 1, GDT_Float32, 0, 0 ); > > ... > > that's ok > > > > > > > > Instead if I put coordinates (*x*, *somethingelse*) where > > 0<*somethingelse*<370 and > > 0<*x*: > > ... > > pointerToBand->RasterIO( GF_Read, *x*, *somethingelse* > > , nXSize, 1, elevation, nXSize, 1, GDT_Float32, 0, 0 ); > > ... > > that doesn't work :( > > > > I opened myFile.dem with a text editor and I've seen the whole matrix as > a > > linecode values... > > There's something I cannot understand obviously, any tips would be really > > appreciated, thanks in advance, > > Regards > > Carmelo >
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