def make_extent_from_dem(dem, output_location):
arcpy.CheckOutExtension("Spatial")
environments = store_environments(["mask", "extent", "outputCoordinateSystem"])
try:
temp_raster_filename = generate_gdb_filename(scratch=True)
dem_properties = arcpy.Describe(dem)
arcpy.env.outputCoordinateSystem = dem_properties.spatialReference # set the spatial reference environment variable so that the constant raster gets created properly
geoprocessing_log.info("Creating Constant Raster")
arcpy.env.mask = dem
raster = arcpy.sa.CreateConstantRaster(constant_value=1, data_type="INTEGER", cell_size=10, extent=dem)
geoprocessing_log.info("Saving to output filename")
print(temp_raster_filename)
raster.save(temp_raster_filename)
geoprocessing_log.info("Converting Raster to Polygon")
arcpy.RasterToPolygon_conversion(temp_raster_filename, output_location, simplify=False, raster_field="Value")
#arcpy.Delete_management(temp_raster_filename)
finally:
arcpy.CheckInExtension("Spatial")
reset_environments(environments)
def land_use(nlcd_layer, search_area, excluded_types, tiger_lines,
census_places, crs, workspace):
arcpy.CheckOutExtension("spatial")
geoprocessing_log.info("Extracting NLCD raster to search area")
nlcd_in_area = arcpy.sa.ExtractByMask(nlcd_layer, search_area)
avoid_types = [exclude.value for exclude in excluded_types]
thresholded_raster = nlcd_in_area
for avoid in avoid_types: # this is inefficient, but I couldn't get it to work with a "not in" and I need something that works for n number of values
thresholded_raster = arcpy.sa.Con(thresholded_raster != avoid,
thresholded_raster, 0)
scratch_raster = generate_gdb_filename("temp_raster", scratch=True)
thresholded_raster.save(
scratch_raster) # save it so we can use it for environment variables
stored_environments = store_environments(
('cellSize', 'mask', 'extent', 'snapRaster')
) # cache the env vars so we can reset them at the end of this function
arcpy.env.cellSize = scratch_raster
arcpy.env.mask = scratch_raster
arcpy.env.extent = scratch_raster
arcpy.env.snapRaster = scratch_raster
roads_mask = make_road_mask(tiger_lines,
census_places=census_places,
search_area=search_area)
roads_raster = generate_gdb_filename("roads_raster")
geoprocessing_log.info("Converting roads mask to raster")
try:
arcpy.PolygonToRaster_conversion(roads_mask, "OBJECTID", roads_raster)
#arcpy.CalculateStatistics_management(roads_raster) # crashes for invalid statistics unless we run this after the conversion
except:
geoprocessing_log.error(
"Error creating raster: {0:s} - from roads mask: {1:s}".format(
roads_raster, roads_mask))
raise
# Raster Calculations
final_nlcd = arcpy.sa.Con(arcpy.sa.IsNull(arcpy.sa.Raster(roads_raster)),
thresholded_raster, 1)
intermediate_raster = generate_gdb_filename("intermediate_nlcd_mask")
projected_raster = generate_gdb_filename("projected_nlcd_mask",
gdb=workspace)
final_nlcd.save(intermediate_raster)
reset_environments(stored_environments)
geoprocessing_log.info("Reprojecting final raster")
arcpy.ProjectRaster_management(intermediate_raster,
projected_raster,
out_coor_system=crs)
filtered_nlcd_poly = filter_patches.convert_and_filter_by_code(
projected_raster, filter_value=0)
return filtered_nlcd_poly
def land_use(nlcd_layer, search_area, excluded_types, tiger_lines, census_places, crs, workspace):
arcpy.CheckOutExtension("spatial")
geoprocessing_log.info("Extracting NLCD raster to search area")
nlcd_in_area = arcpy.sa.ExtractByMask(nlcd_layer, search_area)
avoid_types = [exclude.value for exclude in excluded_types]
thresholded_raster = nlcd_in_area
for (
avoid
) in (
avoid_types
): # this is inefficient, but I couldn't get it to work with a "not in" and I need something that works for n number of values
thresholded_raster = arcpy.sa.Con(thresholded_raster != avoid, thresholded_raster, 0)
scratch_raster = generate_gdb_filename("temp_raster", scratch=True)
thresholded_raster.save(scratch_raster) # save it so we can use it for environment variables
stored_environments = store_environments(
("cellSize", "mask", "extent", "snapRaster")
) # cache the env vars so we can reset them at the end of this function
arcpy.env.cellSize = scratch_raster
arcpy.env.mask = scratch_raster
arcpy.env.extent = scratch_raster
arcpy.env.snapRaster = scratch_raster
roads_mask = make_road_mask(tiger_lines, census_places=census_places, search_area=search_area)
roads_raster = generate_gdb_filename("roads_raster")
geoprocessing_log.info("Converting roads mask to raster")
try:
arcpy.PolygonToRaster_conversion(roads_mask, "OBJECTID", roads_raster)
# arcpy.CalculateStatistics_management(roads_raster) # crashes for invalid statistics unless we run this after the conversion
except:
geoprocessing_log.error(
"Error creating raster: {0:s} - from roads mask: {1:s}".format(roads_raster, roads_mask)
)
raise
# Raster Calculations
final_nlcd = arcpy.sa.Con(arcpy.sa.IsNull(arcpy.sa.Raster(roads_raster)), thresholded_raster, 1)
intermediate_raster = generate_gdb_filename("intermediate_nlcd_mask")
projected_raster = generate_gdb_filename("projected_nlcd_mask", gdb=workspace)
final_nlcd.save(intermediate_raster)
reset_environments(stored_environments)
geoprocessing_log.info("Reprojecting final raster")
arcpy.ProjectRaster_management(intermediate_raster, projected_raster, out_coor_system=crs)
filtered_nlcd_poly = filter_patches.convert_and_filter_by_code(projected_raster, filter_value=0)
return filtered_nlcd_poly