env.extent = Australia_extent maxent_raster = arcpy.sa.Raster(maxent_model) # start a list of layers to delete at the end layers_to_delete = [] ## Buffer the full set of sequenced locations STEPS 1 & 2 print "Buffering all points\n" point_buffer = arcpy.sa.EucDistance(points, buffer_dist, grid_resolution) point_buffer.save("all_points_buf") ## once the code is working, no need to save this layer layers_to_delete.append("all_points_buf") ## from the points shapefile, get a list of the lineages print "Lineage list\n" lineage_list = LineageFunctions.getFieldValues(points, Lineage_field_name) print "Lineages:" for lineage in lineage_list: print " ", lineage # calculate the extent for weight grids points_properties = arcpy.Describe(points) points_extent = points_properties.extent buffer_ratio = 1 + additional_buffer extent_buffer = buffer_dist * buffer_ratio # new extent is the same as points layer + a buffer # but where the extended buffer goes beyond the extent of Australia, limit to Australia xmin = math.floor(max([points_extent.xmin - extent_buffer, Australia_extent.XMin])) ymin = math.floor(max([points_extent.ymin - extent_buffer, Australia_extent.YMin])) xmax = math.ceil(min([points_extent.xmax + extent_buffer, Australia_extent.XMax]))