def generate_streamed_json_response():
cartogram_gen_output = b''
current_loading_point = "null"
# We have to format our JSON manually, since we're not sending a complete object.
# On the client side, Oboe.js is intelligent enough to parse this and get the loading information and cartogram output
yield '{"loading_progress_points":['
for source, line in cartwrap.generate_cartogram(
cartogram_handler.gen_area_data(values),
cartogram_handler.get_gen_file(), settings.CARTOGRAM_EXE):
if source == "stdout":
cartogram_gen_output += line
else:
s = re.search(r'max\. abs\. area error: (.+)', line.decode())
if s != None:
current_loading_point = s.groups(1)[0]
# We always include the loading progress, even if it hasn't changed.
# This makes life easier on the client side
yield '{{"loading_point": {}, "stderr_line": "{}"}},'.format(
current_loading_point, line.decode())
# We create a fake last entry because you can't have dangling commas in JSON
yield '{"loading_point":0, "stderr_line": ""}],"cartogram_data":'
if cartogram_handler.expect_geojson_output():
# Just confirm that we've been given valid JSON. Calculate the extrema if necessary
cartogram_json = json.loads(cartogram_gen_output.decode())
if "bbox" not in cartogram_json:
cartogram_json[
"bbox"] = geojson_extrema.get_extrema_from_geojson(
cartogram_json)
else:
cartogram_json = gen2dict.translate(
io.StringIO(cartogram_gen_output.decode()),
settings.CARTOGRAM_COLOR, cartogram_handler.remove_holes())
cartogram_json['unique_sharing_key'] = unique_sharing_key
cartogram_json = json.dumps(cartogram_json)
if settings.USE_DATABASE:
cartogram_entry = CartogramEntry.query.filter_by(
string_key=unique_sharing_key).first()
if cartogram_entry != None:
cartogram_entry.cartogram_data = cartogram_json
db.session.commit()
yield cartogram_json
yield "}"
def cartogram():
if 'handler' not in request.form:
return Response('{"error":"badrequest"}',
status=400,
content_type="application/json")
if request.form['handler'] not in cartogram_handlers:
return Response('{"error":"badhandler"}',
status=404,
content_type="application/json")
handler = request.form['handler']
cartogram_handler = cartogram_handlers[handler]
if 'values' not in request.form:
return Response('{"error":"badrequest"}',
status=400,
content_type="application/json")
values = request.form['values'].split(";")
# The existing verificaiton code expects all floats. To avoid modifying it, we replace the string "NA" with the
# number 0.0 for verification purposes only.
values_to_verify = []
try:
for i in range(len(values)):
if values[i] == "NA":
values_to_verify.append(0.0)
else:
values[i] = float(values[i])
values_to_verify.append(values[i])
except ValueError:
return Response('{"error":"badvalues"}',
status=400,
content_type="application/json")
if cartogram_handler.validate_values(values_to_verify) != True:
return Response('{"error":"badvalues"}',
status=400,
content_type="application/json")
unique_sharing_key = ""
if 'unique_sharing_key' in request.form:
unique_sharing_key = request.form['unique_sharing_key']
lambda_result = awslambda.generate_cartogram(
cartogram_handler.gen_area_data(values),
cartogram_handler.get_gen_file(), settings.CARTOGRAM_LAMBDA_URL,
settings.CARTOGRAM_LAMDA_API_KEY, unique_sharing_key)
cartogram_gen_output = lambda_result['stdout']
if cartogram_handler.expect_geojson_output():
# Just confirm that we've been given valid JSON. Calculate the extrema if necessary
cartogram_json = json.loads(cartogram_gen_output)
if "bbox" not in cartogram_json:
cartogram_json["bbox"] = geojson_extrema.get_extrema_from_geojson(
cartogram_json)
else:
cartogram_json = gen2dict.translate(io.StringIO(cartogram_gen_output),
settings.CARTOGRAM_COLOR,
cartogram_handler.remove_holes())
cartogram_json['unique_sharing_key'] = unique_sharing_key
if settings.USE_DATABASE:
cartogram_entry = CartogramEntry.query.filter_by(
string_key=unique_sharing_key).first()
if cartogram_entry != None:
cartogram_entry.cartogram_data = json.dumps(cartogram_json)
db.session.commit()
return Response(json.dumps({'cartogram_data': cartogram_json}),
content_type='application/json',
status=200)
cartogram_output = ""
for source, line in cartwrap.generate_cartogram(area_data,
handler.get_gen_file(),
settings.CARTOGRAM_EXE):
if source == "stderr":
print("Generating {}: {}".format(sysname, line.decode()))
else:
cartogram_output += line.decode()
if handler.expect_geojson_output():
cartogram_json = json.loads(cartogram_output)
if "bbox" not in cartogram_json:
cartogram_json["bbox"] = geojson_extrema.get_extrema_from_geojson(
cartogram_json)
else:
cartogram_json = gen2dict.translate(io.StringIO(cartogram_output),
settings.CARTOGRAM_COLOR,
handler.remove_holes())
cartogram_json['tooltip'] = tooltip
with open("static/cartdata/{}/population.json".format(sysname),
'w') as population_json_file:
json.dump(cartogram_json, population_json_file)
def generate_cartogram_set(maps, cartogram_executable, default_color):
maximum_progress = 95.0
current_progress = 0.0
main_average_density = 0.0
map_number = 1
for cart_map in maps:
cartogram_gen = ""
cartogram_json = {}
cartogram_area = 0.0
cartogram_average_density = 0.0
initial_area_error = None
one_region_cartogram = False
yield "loading", {
'loading_point': current_progress,
'stderr_line':
'Computing Map {} of {}'.format(map_number, len(maps))
}
for source, line in generate_cartogram(cart_map['area_data'],
cart_map['gen_file'],
cartogram_executable):
if source == "stdout":
map_gen += line
else:
s = re.search(r'max\. abs\. area error: (.+)', line.decode())
if s != None:
if initial_area_error == None:
initial_area_error = float(s.groups(1)[0])
current_progress = (
0 if map_number == 1 else maximum_progress /
map_number) + (maximum_progress / len(maps)) * 0.2
else:
current_progress = (
0 if map_number == 1 else maximum_progress /
map_number) + (
((initial_area_error - float(s.groups(1)[0])) /
((initial_area_error - 0.01))) *
((maximum_progress / len(maps))))
area_search = re.search(r'total cartogram area: (.+)',
line.decode())
if area_search != None:
cartogram_area = float(area_search.groups(1)[0])
one_region_search = re.search(
r'WARNING: There is only one region. The output cartogram will',
line.decode())
if one_region_search != None:
one_region_cartogram = True
yield "loading", {
'loading_point': current_progress,
'stderr_line': line.decode()
}
# Now we want to calculate the average density
cartogram_average_density = sum([
float(entry.split(' ')[1])
for entry in cart_map['area_data'].split('\n')
]) / cartogram_area
if map_number == 1:
main_average_density = cartogram_average_density
cartogram_json = gen2dict.translate(
io.StringIO(cartogram_gen.decode()), default_color)
# If we're not dealing with the main map (i.e., the first one) and we
# only one region, then we need to do the scaling here.
if map_number != 1 and one_region_cartogram:
# In this case, cartogram_average_density is the same as the user-
# supplied area for the one region in this map.
scaling_factor = math.sqrt(cartogram_average_density /
main_average_density)
for feature in cartogram_json['features']:
for pair in feature['coordinates']:
pair[0] *= scaling_factor
pair[1] *= scaling_factor
yield "output", cartogram_json
map_number += 1
import gen2dict
import sys
with open(sys.argv[1]) as map_gen_file:
gen_json = gen2dict.translate(map_gen_file, "#aaaaaa", True)
with open(sys.argv[2], "w") as svg_file:
max_x = gen_json["extrema"]["max_x"]
min_x = gen_json["extrema"]["min_x"]
max_y = gen_json["extrema"]["max_y"]
min_y = gen_json["extrema"]["min_y"]
width = max_x - min_x
height = max_y - min_y
scale = 750.0 / width
width *= scale
height *= scale
def x_transform(x):
return (x - min_x) * scale
def y_transform(y):
return ((max_y - min_y) - (y - min_y)) * scale
svg_file.write("""<svg version="1.1"
baseProfile="full"