docs: def to_tiff(self, filename):
          '''
          geo.to_tiff(filename)
  
          Saves GeoRaster as geotiff filename.tif with type datatype
  
          If GeoRaster does not have datatype, then it tries to assign a type.
          You can assign the type yourself by setting
           geo.datatype = 'gdal.GDT_'+type
          '''
          if self.datatype is None:
              self.datatype = gdal_array.NumericTypeCodeToGDALTypeCode(self.raster.data.dtype)
              if self.datatype is None:
                  if self.raster.data.dtype.name.find('int') !=- 1:
                      self.raster = self.raster.astype(np.int32)
                      self.datatype = gdal_array.NumericTypeCodeToGDALTypeCode(self.raster.data.dtype)
                  else:
                      self.raster = self.raster.astype(np.float64)
                      self.datatype = gdal_array.NumericTypeCodeToGDALTypeCode(self.raster.data.dtype)
          self.raster.data[self.raster.mask] = self.nodata_value
          create_geotiff(filename, self.raster, gdal.GetDriverByName('GTiff'), self.nodata_value,
                         self.shape[1], self.shape[0], self.geot, self.projection, self.datatype)