def process_local_slope(dem=None,
slope=None,
max_slope=30,
mask=None,
return_type="polygon",
workspace=None):
"""
:param dem: The DEM to process
:param slope: If slope is already processed, use this instead.
:param max_slope: The maximum slope in degrees that will be considered suitable for building
:param mask: A polygon or raster mask to use as the processing area (arcpy.env.mask/Analysis Mask environment)
:param return_type: whether to return a polygon feature class or a raster. Default is polygon, where raster will be processed to polygon automatically. Options are "polygon" or "raster"
:return:
"""
if not dem and not slope:
raise ValueError(
"Must provide either a slope raster or a DEM raster. Either parameter 'dem' or parameter 'slope' must be defined."
)
arcpy.CheckOutExtension("Spatial")
if not slope:
arcpy.env.mask = mask
logger.info("Processing raster to slope")
mask_raster = arcpy.sa.ExtractByMask(
dem, mask
) # mask environment variable hasn't been working - force extraction
slope_raster = arcpy.sa.Slope(mask_raster, output_measurement="DEGREE")
else:
slope_raster = arcpy.sa.ExtractByMask(
slope, mask
) # mask environment variable hasn't been working - force extraction
logger.info("Thresholding raster")
threshold_raster = slope_raster < max_slope
raster_name = generate_gdb_filename("slope_raster", gdb=workspace)
logger.info("Saving raster to disk")
threshold_raster.save(raster_name)
arcpy.CheckInExtension("Spatial")
if return_type.lower() == "polygon":
logger.info("Converting to polygons")
new_name = convert_and_filter_by_code(raster_name, filter_value=1)
poly_name = generate_gdb_filename("slope_polygon", gdb=workspace)
arcpy.CopyFeatures_management(new_name, poly_name)
return poly_name
elif return_type.lower() == "raster":
return raster_name
else:
raise ValueError(
"Invalid parameter for return_type. Must be either \"raster\" or \"polygon\""
)
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
def process_local_slope(dem=None, slope=None, max_slope=30, mask=None, return_type="polygon", workspace=None):
"""
:param dem: The DEM to process
:param slope: If slope is already processed, use this instead.
:param max_slope: The maximum slope in degrees that will be considered suitable for building
:param mask: A polygon or raster mask to use as the processing area (arcpy.env.mask/Analysis Mask environment)
:param return_type: whether to return a polygon feature class or a raster. Default is polygon, where raster will be processed to polygon automatically. Options are "polygon" or "raster"
:return:
"""
if not dem and not slope:
raise ValueError("Must provide either a slope raster or a DEM raster. Either parameter 'dem' or parameter 'slope' must be defined.")
arcpy.CheckOutExtension("Spatial")
if not slope:
arcpy.env.mask = mask
logger.info("Processing raster to slope")
mask_raster = arcpy.sa.ExtractByMask(dem, mask) # mask environment variable hasn't been working - force extraction
slope_raster = arcpy.sa.Slope(mask_raster, output_measurement="DEGREE")
else:
slope_raster = arcpy.sa.ExtractByMask(slope, mask) # mask environment variable hasn't been working - force extraction
logger.info("Thresholding raster")
threshold_raster = slope_raster < max_slope
raster_name = generate_gdb_filename("slope_raster", gdb=workspace)
logger.info("Saving raster to disk")
threshold_raster.save(raster_name)
arcpy.CheckInExtension("Spatial")
if return_type.lower() == "polygon":
logger.info("Converting to polygons")
new_name = convert_and_filter_by_code(raster_name, filter_value=1)
poly_name = generate_gdb_filename("slope_polygon", gdb=workspace)
arcpy.CopyFeatures_management(new_name, poly_name)
return poly_name
elif return_type.lower() == "raster":
return raster_name
else:
raise ValueError("Invalid parameter for return_type. Must be either \"raster\" or \"polygon\"")
