def clean_up():
"""
Removes all auxiliary files
"""
auxiliary_dir = join(inputs[OUTPUT_LOCATION], AUXILIARY_DIR_NAME)
od_cost_matrix_layer = join(auxiliary_dir, OD_COST_MATRIX_LAYER_NAME)
od_cost_matrix_lines = join(auxiliary_dir, OD_COST_MATRIX_LINES)
temp_adj_dbf_name = "%s~.dbf" % adj_dbf_name[-4]
temp_adj_dbf = join(inputs[OUTPUT_LOCATION], temp_adj_dbf_name)
partial_adj_dbf = join(auxiliary_dir, PARTIAL_ADJACENCY_LIST_NAME)
polygons = join(auxiliary_dir, POLYGONS_SHAPEFILE_NAME)
raster = join(auxiliary_dir, RASTER_NAME)
polygons_layer = join(auxiliary_dir, POLYGONS_LAYER_NAME)
input_points_layer = join(auxiliary_dir, INPUT_POINTS_LAYER_NAME)
for delete_path in [input_points_layer, polygons_layer, raster, polygons,
partial_adj_dbf, temp_adj_dbf, od_cost_matrix_lines, od_cost_matrix_layer,
auxiliary_dir]:
delete(delete_path)
def clean_up():
"""
Removes all auxiliary files
"""
auxiliary_dir = join(inputs[OUTPUT_LOCATION], AUXILIARY_DIR_NAME)
od_cost_matrix_layer = join(auxiliary_dir, OD_COST_MATRIX_LAYER_NAME)
od_cost_matrix_lines = join(auxiliary_dir, OD_COST_MATRIX_LINES)
temp_adj_dbf_name = "%s~.dbf" % adj_dbf_name[-4]
temp_adj_dbf = join(inputs[OUTPUT_LOCATION], temp_adj_dbf_name)
partial_adj_dbf = join(auxiliary_dir, PARTIAL_ADJACENCY_LIST_NAME)
polygons = join(auxiliary_dir, POLYGONS_SHAPEFILE_NAME)
raster = join(auxiliary_dir, RASTER_NAME)
polygons_layer = join(auxiliary_dir, POLYGONS_LAYER_NAME)
input_points_layer = join(auxiliary_dir, INPUT_POINTS_LAYER_NAME)
for delete_path in [input_points_layer, polygons_layer, raster, polygons,
partial_adj_dbf, temp_adj_dbf, od_cost_matrix_lines, od_cost_matrix_layer,
auxiliary_dir]:
delete(delete_path)
def compute_adjacency_list(input_points, input_network, id_attribute,
impedance_attribute, accumulator_attributes,
search_radius, output_location, adj_dbf_name):
"""
|input_points|: point shape file marking entity (e.g. building) locations
|input_network|: street network in which |input_points| is located
|id_attribute|: the name of attribute that distinguishes between input points
|impedance_attribute|: distance between neighboring nodes will be based on
this attribute
|accumulator_attributes|: distance between neighboring nodes will also be
recorded for these attributes
|search_radius|: the maximum extent for centrality computation
|output_location|: adjacency list dbf will be saved here
|adj_dbf_name|: the name of the adjacency list dbf
"""
# Number of points in |input_points|
input_point_count = int(GetCount_management(input_points).getOutput(0))
# Make a directory to store all auxiliary files
auxiliary_dir = join(output_location, AUXILIARY_DIR_NAME)
if not Exists(auxiliary_dir):
mkdir(auxiliary_dir)
# Record the edge and junction source names of |input_network|
junction_feature, edge_feature = network_features(input_network)
# Calculate network locations if not already calculated
test_input_point = UpdateCursor(input_points).next()
locations_calculated = all(
row_has_field(test_input_point, field)
for field in NETWORK_LOCATION_FIELDS)
if not locations_calculated:
calculate_network_locations(input_points, input_network)
# Calculate barrier cost per input point if not already calculated
barrier_costs_calculated = row_has_field(test_input_point,
trim(BARRIER_COST_FIELD))
if not barrier_costs_calculated:
AddMessage(BARRIER_COST_COMPUTATION_STARTED)
# Add |BARRIER_COST_FIELD| column in |input_points|
AddField_management(in_table=input_points,
field_name=trim(BARRIER_COST_FIELD),
field_type="DOUBLE",
field_is_nullable="NON_NULLABLE")
# Initialize a dictionary to store the frequencies of (SnapX, SnapY) values
xy_count = {}
# A method to retrieve a (SnapX, SnapY) pair for a row in |input_points|
get_xy = lambda row: (row.getValue(trim("SnapX")),
row.getValue(trim("SnapY")))
barrier_pre_progress = Progress_Bar(input_point_count, 1,
BARRIER_COST_PRE_PROCESSING)
rows = UpdateCursor(input_points)
for row in rows:
snap_xy = get_xy(row)
if snap_xy in xy_count:
xy_count[snap_xy] += 1
else:
xy_count[snap_xy] = 1
barrier_pre_progress.step()
# Populate |BARRIER_COST_FIELD|, this will be used in OD matrix computation
barrier_progress = Progress_Bar(input_point_count, 1,
BARRIER_COST_COMPUTATION)
rows = UpdateCursor(input_points)
for row in rows:
barrier_cost = BARRIER_COST / xy_count[get_xy(row)]
row.setValue(trim(BARRIER_COST_FIELD), barrier_cost)
rows.updateRow(row)
barrier_progress.step()
AddMessage(BARRIER_COST_COMPUTATION_FINISHED)
# Necessary files
od_cost_matrix_layer = join(auxiliary_dir, OD_COST_MATRIX_LAYER_NAME)
od_cost_matrix_lines = join(od_cost_matrix_layer, OD_COST_MATRIX_LINES)
temp_adj_dbf_name = TEMP_ADJACENCY_DBF_NAME(adj_dbf_name)
temp_adj_dbf = join(output_location, temp_adj_dbf_name)
adj_dbf = join(output_location, adj_dbf_name)
partial_adj_dbf = join(auxiliary_dir, PARTIAL_ADJACENCY_LIST_NAME)
polygons = join(auxiliary_dir, POLYGONS_SHAPEFILE_NAME)
raster = join(auxiliary_dir, RASTER_NAME)
polygons_layer = join(auxiliary_dir, POLYGONS_LAYER_NAME)
input_points_layer = join(auxiliary_dir, INPUT_POINTS_LAYER_NAME)
# Make sure none of these files already exists
for path in [
od_cost_matrix_layer, temp_adj_dbf, adj_dbf, partial_adj_dbf,
polygons, raster, polygons_layer, input_points_layer,
od_cost_matrix_lines
]:
delete(path)
# Cutoff radius for OD matrix computation
cutoff_radius = 2 * BARRIER_COST + min(search_radius, BARRIER_COST / 2)
# Compute OD matrix
MakeODCostMatrixLayer_na(in_network_dataset=input_network,
out_network_analysis_layer=od_cost_matrix_layer,
impedance_attribute=impedance_attribute,
default_cutoff=str(cutoff_radius),
accumulate_attribute_name=accumulator_attributes,
UTurn_policy="ALLOW_UTURNS",
hierarchy="NO_HIERARCHY",
output_path_shape="NO_LINES")
# Determine raster cell size
points_per_raster_cell = OD_MATRIX_ENTRIES / input_point_count
raster_cell_count = max(1, input_point_count / points_per_raster_cell)
input_points_extent = Describe(input_points).Extent
raster_cell_area = (input_points_extent.width *
input_points_extent.height / raster_cell_count)
raster_cell_size = int(sqrt(raster_cell_area))
# Construct |raster| from |input_points|
PointToRaster_conversion(in_features=input_points,
value_field=id_attribute,
out_rasterdataset=raster,
cell_assignment="MOST_FREQUENT",
priority_field="NONE",
cellsize=str(raster_cell_size))
# Construct |polygons| from |raster|
RasterToPolygon_conversion(in_raster=raster,
out_polygon_features=polygons,
simplify="NO_SIMPLIFY",
raster_field="VALUE")
# Export empty |od_cost_matrix_lines| to |temp_dbf| to start adjacency list
TableToTable_conversion(in_rows=od_cost_matrix_lines,
out_path=output_location,
out_name=temp_adj_dbf_name)
# Construct |polygons_layer| and |input_points_layer|
for (feature, layer) in [(polygons, polygons_layer),
(input_points, input_points_layer)]:
MakeFeatureLayer_management(in_features=feature, out_layer=layer)
def add_locations(sub_layer, field_mappings=""):
"""
|sub_layer|: one of "Origins", "Destinations", "Barrier Points"
|field_mappings|: field mappings in addition to those for "Name" and
"CurbApproach"
"""
AddLocations_na(in_network_analysis_layer=od_cost_matrix_layer,
sub_layer=sub_layer,
in_table=input_points_layer,
field_mappings=("Name %s #; CurbApproach # 0; %s" %
(id_attribute, field_mappings)),
search_tolerance=SEARCH_TOLERANCE,
search_criteria=("%s SHAPE; %s SHAPE;" %
(junction_feature, edge_feature)),
append="CLEAR",
snap_to_position_along_network="SNAP",
snap_offset=SNAP_OFFSET)
# OD cost matrix destinations
AddMessage(ADDING_DESTINATIONS_STARTED)
SelectLayerByLocation_management(in_layer=input_points_layer)
add_locations("Destinations")
AddMessage(ADDING_DESTINATIONS_FINISHED)
# OD cost matrix point barriers
AddMessage(ADDING_BARRIERS_STARTED)
add_locations("Point Barriers",
("FullEdge # 0; BarrierType # 2;"
"Attr_%s %s #;" %
(impedance_attribute, trim(BARRIER_COST_FIELD))))
AddMessage(ADDING_BARRIERS_FINISHED)
# Compute adjacency list, one raster cell at a time
progress = Progress_Bar(raster_cell_count, 1, STEP_1)
rows = UpdateCursor(polygons)
for row in rows:
# Select the current polygon
SelectLayerByAttribute_management(in_layer_or_view=polygons_layer,
selection_type="NEW_SELECTION",
where_clause="FID = %s" %
str(row.FID))
# Origins
SelectLayerByLocation_management(in_layer=input_points_layer,
select_features=polygons_layer)
add_locations("Origins")
# Solve OD Cost matrix
Solve_na(in_network_analysis_layer=od_cost_matrix_layer,
ignore_invalids="SKIP")
# Add origin and destination fields to the adjacency list dbf
for (index, field) in [(0, ORIGIN_ID_FIELD_NAME),
(1, DESTINATION_ID_FIELD_NAME)]:
CalculateField_management(in_table=od_cost_matrix_lines,
field=field,
expression="!Name!.split(' - ')[%d]" %
index,
expression_type="PYTHON")
# Record actual distance between neighboring nodes
distance_field = "Total_%s" % impedance_attribute
CalculateField_management(in_table=od_cost_matrix_lines,
field=distance_field,
expression="!%s! - 2 * %d" %
(distance_field, BARRIER_COST),
expression_type="PYTHON")
# Append result to |temp_adj_dbf|
TableToTable_conversion(in_rows=od_cost_matrix_lines,
out_path=auxiliary_dir,
out_name=PARTIAL_ADJACENCY_LIST_NAME)
Append_management(inputs=partial_adj_dbf,
target=temp_adj_dbf,
schema_type="TEST")
progress.step()
# Copy data from |temp_adj_dbf| to |adj_dbf|
Rename_management(in_data=temp_adj_dbf, out_data=adj_dbf)
# Clean up
for path in [
od_cost_matrix_layer, partial_adj_dbf, polygons, raster,
polygons_layer, input_points_layer, auxiliary_dir
]:
delete(path)
def compute_adjacency_list(input_points, input_network, id_attribute,
impedance_attribute, accumulator_attributes, search_radius, output_location,
adj_dbf_name):
"""
|input_points|: point shape file marking entity (e.g. building) locations
|input_network|: street network in which |input_points| is located
|id_attribute|: the name of attribute that distinguishes between input points
|impedance_attribute|: distance between neighboring nodes will be based on
this attribute
|accumulator_attributes|: distance between neighboring nodes will also be
recorded for these attributes
|search_radius|: the maximum extent for centrality computation
|output_location|: adjacency list dbf will be saved here
|adj_dbf_name|: the name of the adjacency list dbf
"""
# Number of points in |input_points|
input_point_count = int(GetCount_management(input_points).getOutput(0))
# Make a directory to store all auxiliary files
auxiliary_dir = join(output_location, AUXILIARY_DIR_NAME)
if not Exists(auxiliary_dir):
mkdir(auxiliary_dir)
# Record the edge and junction source names of |input_network|
edge_feature = None
junction_feature = None
for source in Describe(input_network).sources:
if source.sourceType == EDGE_FEATURE:
edge_feature = source.name
elif source.sourceType in JUNCTION_FEATURE:
junction_feature = source.name
if edge_feature == None:
AddWarning(WARNING_NO_EDGE_FEATURE(input_network))
raise Invalid_Input_Exception("Input Network")
if junction_feature == None:
AddWarning(WARNING_NO_JUNCTION_FEATURE(input_network))
raise Invalid_Input_Exception("Input Network")
# Calculate network locations if not already calculated
test_input_point = UpdateCursor(input_points).next()
locations_calculated = all(row_has_field(test_input_point, field)
for field in NETWORK_LOCATION_FIELDS)
if not locations_calculated:
AddMessage(CALCULATE_LOCATIONS_STARTED)
CalculateLocations_na(in_point_features=input_points,
in_network_dataset=input_network,
search_tolerance=SEARCH_TOLERANCE,
search_criteria=("%s SHAPE; %s SHAPE;" %
(junction_feature, edge_feature)),
exclude_restricted_elements="INCLUDE")
AddMessage(CALCULATE_LOCATIONS_FINISHED)
# Calculate barrier cost per input point if not already calculated
barrier_costs_calculated = row_has_field(test_input_point,
trim(BARRIER_COST_FIELD))
if not barrier_costs_calculated:
AddMessage(BARRIER_COST_COMPUTATION_STARTED)
# Add |BARRIER_COST_FIELD| column in |input_points|
AddField_management(in_table=input_points,
field_name=trim(BARRIER_COST_FIELD), field_type="DOUBLE",
field_is_nullable="NON_NULLABLE")
# Initialize a dictionary to store the frequencies of (SnapX, SnapY) values
xy_count = {}
# A method to retrieve a (SnapX, SnapY) pair for a row in |input_points|
get_xy = lambda row: (row.getValue(trim("SnapX")),
row.getValue(trim("SnapY")))
barrier_pre_progress = Progress_Bar(input_point_count, 1,
BARRIER_COST_PRE_PROCESSING)
rows = UpdateCursor(input_points)
for row in rows:
snap_xy = get_xy(row)
if snap_xy in xy_count:
xy_count[snap_xy] += 1
else:
xy_count[snap_xy] = 1
barrier_pre_progress.step()
# Populate |BARRIER_COST_FIELD|, this will be used in OD matrix computation
barrier_progress = Progress_Bar(input_point_count, 1,
BARRIER_COST_COMPUTATION)
rows = UpdateCursor(input_points)
for row in rows:
barrier_cost = BARRIER_COST / xy_count[get_xy(row)]
row.setValue(trim(BARRIER_COST_FIELD), barrier_cost)
rows.updateRow(row)
barrier_progress.step()
AddMessage(BARRIER_COST_COMPUTATION_FINISHED)
# Necessary files
od_cost_matrix_layer = join(auxiliary_dir, OD_COST_MATRIX_LAYER_NAME)
od_cost_matrix_lines = join(od_cost_matrix_layer, OD_COST_MATRIX_LINES)
temp_adj_dbf_name = "%s~.dbf" % adj_dbf_name[:-4]
temp_adj_dbf = join(output_location, temp_adj_dbf_name)
adj_dbf = join(output_location, adj_dbf_name)
partial_adj_dbf = join(auxiliary_dir, PARTIAL_ADJACENCY_LIST_NAME)
polygons = join(auxiliary_dir, POLYGONS_SHAPEFILE_NAME)
raster = join(auxiliary_dir, RASTER_NAME)
polygons_layer = join(auxiliary_dir, POLYGONS_LAYER_NAME)
input_points_layer = join(auxiliary_dir, INPUT_POINTS_LAYER_NAME)
# Make sure none of these files already exists
for path in [od_cost_matrix_layer, temp_adj_dbf, adj_dbf, partial_adj_dbf,
polygons, raster, polygons_layer, input_points_layer,
od_cost_matrix_lines]:
delete(path)
# Cutoff radius for OD matrix computation
cutoff_radius = 2 * BARRIER_COST + min(search_radius, BARRIER_COST / 2)
# Compute OD matrix
MakeODCostMatrixLayer_na(in_network_dataset=input_network,
out_network_analysis_layer=od_cost_matrix_layer,
impedance_attribute=impedance_attribute,
default_cutoff=str(cutoff_radius),
accumulate_attribute_name=accumulator_attributes,
UTurn_policy="ALLOW_UTURNS", hierarchy="NO_HIERARCHY",
output_path_shape="NO_LINES")
# Determine raster cell size
points_per_raster_cell = OD_MATRIX_ENTRIES / input_point_count
raster_cell_count = max(1, input_point_count / points_per_raster_cell)
input_points_extent = Describe(input_points).Extent
raster_cell_area = (input_points_extent.width * input_points_extent.height /
raster_cell_count)
raster_cell_size = int(sqrt(raster_cell_area))
# Construct |raster| from |input_points|
PointToRaster_conversion(in_features=input_points,
value_field=id_attribute, out_rasterdataset=raster,
cell_assignment="MOST_FREQUENT", priority_field="NONE",
cellsize=str(raster_cell_size))
# Construct |polygons| from |raster|
RasterToPolygon_conversion(in_raster=raster,
out_polygon_features=polygons, simplify="NO_SIMPLIFY",
raster_field="VALUE")
# Export empty |od_cost_matrix_lines| to |temp_dbf| to start adjacency list
TableToTable_conversion(in_rows=od_cost_matrix_lines,
out_path=output_location, out_name=temp_adj_dbf_name)
# Construct |polygons_layer| and |input_points_layer|
for (feature, layer) in [(polygons, polygons_layer),
(input_points, input_points_layer)]:
MakeFeatureLayer_management(in_features=feature, out_layer=layer)
def add_locations(sub_layer, field_mappings=""):
"""
|sub_layer|: one of "Origins", "Destinations", "Barrier Points"
|field_mappings|: field mappings in addition to those for "Name" and
"CurbApproach"
"""
AddLocations_na(in_network_analysis_layer=od_cost_matrix_layer,
sub_layer=sub_layer, in_table=input_points_layer,
field_mappings=("Name %s #; CurbApproach # 0; %s" %
(id_attribute, field_mappings)),
search_tolerance=SEARCH_TOLERANCE,
search_criteria=("%s SHAPE; %s SHAPE;" %
(junction_feature, edge_feature)),
append="CLEAR", snap_to_position_along_network="SNAP",
snap_offset=SNAP_OFFSET)
# OD cost matrix destinations
AddMessage(ADDING_DESTINATIONS_STARTED)
SelectLayerByLocation_management(in_layer=input_points_layer)
add_locations("Destinations")
AddMessage(ADDING_DESTINATIONS_FINISHED)
# OD cost matrix point barriers
AddMessage(ADDING_BARRIERS_STARTED)
add_locations("Point Barriers", ("FullEdge # 0; BarrierType # 2;"
"Attr_%s %s #;" % (impedance_attribute, trim(BARRIER_COST_FIELD))))
AddMessage(ADDING_BARRIERS_FINISHED)
# Compute adjacency list, one raster cell at a time
progress = Progress_Bar(raster_cell_count, 1, STEP_1)
rows = UpdateCursor(polygons)
for row in rows:
# Select the current polygon
SelectLayerByAttribute_management(in_layer_or_view=polygons_layer,
selection_type="NEW_SELECTION", where_clause="FID = %s" % str(row.FID))
# Origins
SelectLayerByLocation_management(in_layer=input_points_layer,
select_features=polygons_layer)
add_locations("Origins")
# Solve OD Cost matrix
Solve_na(in_network_analysis_layer=od_cost_matrix_layer,
ignore_invalids="SKIP")
# Add origin and destination fields to the adjacency list dbf
for (index, field) in [(0, ORIGIN_ID_FIELD_NAME),
(1, DESTINATION_ID_FIELD_NAME)]:
CalculateField_management(in_table=od_cost_matrix_lines,
field=field, expression="!Name!.split(' - ')[%d]" % index,
expression_type="PYTHON")
# Record actual distance between neighboring nodes
distance_field = "Total_%s" % impedance_attribute
CalculateField_management(in_table=od_cost_matrix_lines,
field=distance_field,
expression="!%s! - 2 * %d" % (distance_field, BARRIER_COST),
expression_type="PYTHON")
# Append result to |temp_adj_dbf|
TableToTable_conversion(in_rows=od_cost_matrix_lines,
out_path=auxiliary_dir, out_name=PARTIAL_ADJACENCY_LIST_NAME)
Append_management(inputs=partial_adj_dbf, target=temp_adj_dbf,
schema_type="TEST")
progress.step()
# Copy data from |temp_adj_dbf| to |adj_dbf|
Rename_management(in_data=temp_adj_dbf, out_data=adj_dbf)
# Clean up
for path in [od_cost_matrix_layer, partial_adj_dbf, polygons, raster,
polygons_layer, input_points_layer, auxiliary_dir]:
delete(path)