def generate_vector_numeric_map(self, numeric_property):
"""Generate stops array for use with match expression in mapbox template"""
vector_stops = []
function_type = getattr(self,
'{}_function_type'.format(numeric_property))
lookup_property = getattr(self, '{}_property'.format(numeric_property))
numeric_stops = getattr(self, '{}_stops'.format(numeric_property))
default = getattr(self, '{}_default'.format(numeric_property))
if function_type == 'match':
match_width = numeric_stops
# if join data specified as filename or URL, parse JSON to list of Python dicts
if type(self.data) == str:
self.data = geojson_to_dict_list(self.data)
for row in self.data:
# map value to JSON feature using the numeric property
value = numeric_map(row[lookup_property], numeric_stops, default)
# link to vector feature using data_join_property (from JSON object)
vector_stops.append([row[self.data_join_property], value])
return vector_stops
def generate_vector_width_map(self):
"""Generate width stops array for use with match expression in mapbox template"""
vector_stops = []
if self.line_width_function_type == 'match':
match_width = self.line_width_stops
for row in self.data:
# map width to JSON feature using width_property
width = numeric_map(row[self.line_width_property], self.line_width_stops, self.line_width_default)
# link to vector feature using data_join_property (from JSON object)
vector_stops.append([row[self.data_join_property], width])
return vector_stops
def test_numeric_map_exact():
"""Compute mapping for lookup value exactly matching numeric stop in stops"""
stops = [[0.0, 0], [50.0, 5000.0], [1000.0, 100000.0]]
assert numeric_map(50.0, stops, 42) == 5000.0
def test_numeric_map_default():
"""Default value when look up does not match any stop in stops"""
stops = [[0.0, 0], [50.0, 5000.0], [1000.0, 100000.0]]
assert numeric_map(-1.0, stops, 42) == 0
def test_numeric_map_no_stops():
"""Return default if length of stops argument is 0"""
stops = []
assert numeric_map(117.0, stops, 42) == 42
def test_numeric_map_match():
"""Match value from numeric stops"""
match_stops = [['road', 1.0], ['fence', 15.0], ['wall', 10.0]]
assert numeric_map('fence', match_stops, 0.0) == 15.0
def test_numeric_map():
"""Map interpolated (or matched) value from numeric stops"""
stops = [[0.0, 0], [50.0, 5000.0], [1000.0, 100000.0]]
assert numeric_map(117.0, stops, 0.0) == 11700.0
