topic Masking NetCDF file with shapefile in Geoprocessing Questions https://community.esri.com/t5/geoprocessing-questions/masking-netcdf-file-with-shapefile/m-p/350318#M12155 <HTML><HEAD></HEAD><BODY><SPAN>Hello,</SPAN><BR /><BR /><SPAN>I am trying to create a tool which will accept a shapefile, and then use this shapefile as a mask for calculating the mean of various netcdf files.&nbsp; I have read up on the gdal library, but I am very confused on how to use these tools.&nbsp; Instead I have tried to do it with the tools available in arcgis.&nbsp; What I have done in my python script is convert the input shapefile into a raster where all values are 1, then I use the arcpy.RasterToNumpyArray command to convert the raster to a numpy array. I then multiply this array by the arrays I have created from the netcdf files.&nbsp; So the product of the numpy array of the shapefile and the numpy array of the netcdf file should be the array of the netcdf file within the polygon extent, because I masked out all values outside the polygon extent as not a number. The tool runs successfully but my results are off.&nbsp; I have noticed that when I convert the raster of the polygon to a numpy array, the numpy array is much larger than the raster and original polygon.&nbsp; Does anyone know why the RasterToNumpyArray tool would create an array that is much bigger than the raster?&nbsp; The reason I know it is much bigger is because when I convert the product of the numpy arrays back to a raster using the NumpyArrayToRaster command, it is the shape of my input shapfile, but just much larger, and with the same lower left hand corner point.&nbsp; I would really appreciate and insight on what I might be doing wrong.&nbsp; Thank you!</SPAN></BODY></HTML> Thu, 07 Feb 2013 21:48:00 GMT StephenFricke 2013-02-07T21:48:00Z Masking NetCDF file with shapefile https://community.esri.com/t5/geoprocessing-questions/masking-netcdf-file-with-shapefile/m-p/350318#M12155 <HTML><HEAD></HEAD><BODY><SPAN>Hello,</SPAN><BR /><BR /><SPAN>I am trying to create a tool which will accept a shapefile, and then use this shapefile as a mask for calculating the mean of various netcdf files.&nbsp; I have read up on the gdal library, but I am very confused on how to use these tools.&nbsp; Instead I have tried to do it with the tools available in arcgis.&nbsp; What I have done in my python script is convert the input shapefile into a raster where all values are 1, then I use the arcpy.RasterToNumpyArray command to convert the raster to a numpy array. I then multiply this array by the arrays I have created from the netcdf files.&nbsp; So the product of the numpy array of the shapefile and the numpy array of the netcdf file should be the array of the netcdf file within the polygon extent, because I masked out all values outside the polygon extent as not a number. The tool runs successfully but my results are off.&nbsp; I have noticed that when I convert the raster of the polygon to a numpy array, the numpy array is much larger than the raster and original polygon.&nbsp; Does anyone know why the RasterToNumpyArray tool would create an array that is much bigger than the raster?&nbsp; The reason I know it is much bigger is because when I convert the product of the numpy arrays back to a raster using the NumpyArrayToRaster command, it is the shape of my input shapfile, but just much larger, and with the same lower left hand corner point.&nbsp; I would really appreciate and insight on what I might be doing wrong.&nbsp; Thank you!</SPAN></BODY></HTML> Thu, 07 Feb 2013 21:48:00 GMT https://community.esri.com/t5/geoprocessing-questions/masking-netcdf-file-with-shapefile/m-p/350318#M12155 StephenFricke 2013-02-07T21:48:00Z