Files
notifications-admin/app/broadcast_areas/create-broadcast-areas-db.py
Chris Hill-Scott 0fa3e009c9 Remove Sizewell from the demo areas library
We added this for the 25 May demo. We’re unlikely to need it again.

We’re also unlikely to need this library again, so this commit removes
the source and the code that creates it.
2022-03-15 14:40:42 +00:00

453 lines
15 KiB
Python
Executable File
Raw Blame History

This file contains ambiguous Unicode characters
This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
#!/usr/bin/env python
import csv
import pickle
import sys
from math import isclose
from pathlib import Path
import geojson
from notifications_utils.formatters import formatted_list
from notifications_utils.polygons import Polygons
from populations import (
BRYHER,
CITY_OF_LONDON,
MEDIAN_AGE_RANGE_UK,
MEDIAN_AGE_UK,
SMARTPHONE_OWNERSHIP_BY_AGE_RANGE,
estimate_number_of_smartphones_for_population,
)
from repo import BroadcastAreasRepository, rtree_index_path
from rtreelib import Rect, RTree
from shapely import wkt
from shapely.geometry import MultiPolygon, Polygon
source_files_path = Path(__file__).resolve().parent / 'source_files'
point_counts = []
invalid_polygons = []
rtree_index = RTree()
# The hard limit in the CBCs is 6,000 points per polygon. But we also
# care about optimising how quickjly we can process and display polygons
# so we aim for something lower, i.e. enough to give us a good amount of
# precision relative to the accuracy of a cell broadcast
MAX_NUMBER_OF_POINTS_PER_POLYGON = 250
def simplify_geometry(feature):
if feature["type"] == "Polygon":
return [feature["coordinates"][0]]
elif feature["type"] == "MultiPolygon":
return [polygon for polygon, *_holes in feature["coordinates"]]
else:
raise Exception("Unknown type: {}".format(feature["type"]))
def clean_up_invalid_polygons(polygons, indent=" "):
"""
This function expects a list of lists of coordinates defined in degrees
"""
for index, polygon in enumerate(polygons):
shapely_polygon = Polygon(polygon)
# Some of our data has points which are incredibly close
# together. In some cases they are close enough to be duplicates
# at a given precision, which makes an invalid topology. In
# other cases they are close enough that, when converting from
# one coordinate system to another, they shift about enough to
# create self-intersection. The fix in both cases is to reduce
# the precision of the coordinates and then apply simplification
# with a tolerance of 0.
simplified_polygon = wkt.loads(wkt.dumps(
shapely_polygon,
rounding_precision=Polygons.output_precision_in_decimal_places - 1
)).simplify(0)
if simplified_polygon.is_valid:
print( # noqa: T001
f"{indent}Polygon {index + 1}/{len(polygons)} is valid"
)
yield simplified_polygon
else:
invalid_polygons.append(shapely_polygon)
# Weve found polygons where all the points line up, so they
# dont have an area. They wouldnt contribute to a broadcast
# so we can ignore them.
if simplified_polygon.area == 0:
print( # noqa: T001
f"{indent}Polygon {index + 1}/{len(polygons)} has 0 area, skipping"
)
continue
print( # noqa: T001
f"{indent}Polygon {index + 1}/{len(polygons)} needs fixing..."
)
# Buffering with a size of 0 is a trick to make valid
# geometries from polygons that self intersect
buffered = shapely_polygon.buffer(0)
# If the buffering has caused our polygon to split into
# multiple polygons, we need to recursively check them
# instead
if isinstance(buffered, MultiPolygon):
for sub_polygon in clean_up_invalid_polygons(buffered, indent=" "):
yield sub_polygon
continue
# We only care about the exterior of the polygon, not an
# holes in it that may have been created by fixing self
# intersection
fixed_polygon = Polygon(buffered.exterior)
# Make sure the polygon is now valid, and that we havent
# drastically transformed the polygon by fixing it
assert fixed_polygon.is_valid
assert isclose(fixed_polygon.area, shapely_polygon.area, rel_tol=0.001)
print( # noqa: T001
f"{indent}Polygon {index + 1}/{len(polygons)} fixed!"
)
yield fixed_polygon
def polygons_and_simplified_polygons(feature):
if keep_old_polygons:
# cheat and shortcut out
return [], []
raw_polygons = simplify_geometry(feature)
clean_raw_polygons = [
[[x, y] for x, y in polygon.exterior.coords]
for polygon in clean_up_invalid_polygons(raw_polygons)
]
polygons = Polygons(clean_raw_polygons)
full_resolution = polygons.remove_too_small
smoothed = full_resolution.smooth
simplified = smoothed.simplify
if not (len(full_resolution) or len(simplified)):
raise RuntimeError(
'Polygon of 0 size found'
)
print( # noqa: T001
f' Original:{full_resolution.point_count: >5} points'
f' Smoothed:{smoothed.point_count: >5} points'
f' Simplified:{simplified.point_count: >4} points'
)
point_counts.append(simplified.point_count)
if simplified.point_count >= MAX_NUMBER_OF_POINTS_PER_POLYGON:
raise RuntimeError(
'Too many points '
'(adjust Polygons.perimeter_to_simplification_ratio or '
'Polygons.perimeter_to_buffer_ratio)'
)
output = [
full_resolution.as_coordinate_pairs_long_lat,
simplified.as_coordinate_pairs_long_lat,
]
# Check that the simplification process hasnt introduced bad data
for dataset in output:
for polygon in dataset:
assert Polygon(polygon).is_valid
return output + [simplified.utm_crs]
def estimate_number_of_smartphones_in_area(country_or_ward_code):
if country_or_ward_code in CITY_OF_LONDON.WARDS:
# We dont have population figures for wards of the City of
# London. Well leave it empty here and estimate on the fly
# later based on physical area.
print(' Population: N/A') # noqa: T001
return None
# For some reason Bryher is the only ward missing population data, so we
# need to hard code it. For simplicity, lets assume all 84 people who
# live on Bryher are 40 years old
if country_or_ward_code == BRYHER.WD20_CODE:
return BRYHER.POPULATION * SMARTPHONE_OWNERSHIP_BY_AGE_RANGE[MEDIAN_AGE_RANGE_UK]
if country_or_ward_code not in area_to_population_mapping:
raise ValueError(f'No population data for {country_or_ward_code}')
return estimate_number_of_smartphones_for_population(
area_to_population_mapping[country_or_ward_code]
)
test_filepath = source_files_path / "Test.geojson"
ctry19_filepath = source_files_path / "Countries.geojson"
# https://geoportal.statistics.gov.uk/datasets/wards-may-2020-boundaries-uk-bgc
# Converted to geojson manually from SHP because of GeoJSON download limits
wd20_filepath = source_files_path / "Electoral Wards May 2020.geojson"
# http://geoportal.statistics.gov.uk/datasets/local-authority-districts-may-2020-boundaries-uk-bgc
lad20_filepath = source_files_path / "Local Authorities May 2020.geojson"
# https://geoportal.statistics.gov.uk/datasets/counties-and-unitary-authorities-december-2019-boundaries-uk-bgc
ctyua19_filepath = source_files_path / "Counties_and_Unitary_Authorities__December_2019__Boundaries_UK_BGC.geojson"
# http://geoportal.statistics.gov.uk/datasets/ward-to-westminster-parliamentary-constituency-to-local-authority-district-december-2019-lookup-in-the-united-kingdom/data
wd_lad_map_filepath = source_files_path / "Electoral Wards and Local Authorities 2020.geojson"
# https://geoportal.statistics.gov.uk/datasets/lower-tier-local-authority-to-upper-tier-local-authority-december-2019-lookup-in-england-and-wales?where=LTLA19CD%20%3D%20%27E06000045%27
ltla_utla_map_filepath = source_files_path / "Lower_Tier_Local_Authority_to_Upper_Tier_Local_Authority__December_2019__Lookup_in_England_and_Wales.csv" # noqa: E501
# https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/populationestimates/datasets/wardlevelmidyearpopulationestimatesexperimental
population_filepath_england_wales = source_files_path / "Mid-2019_Persons_England_Wales.csv"
# https://www.nrscotland.gov.uk/statistics-and-data/statistics/statistics-by-theme/population/population-estimates/2011-based-special-area-population-estimates/electoral-ward-population-estimates
population_filepath_scotland = source_files_path / "Mid-2019_Persons_Scotland.csv"
population_filepath_northern_ireland = source_files_path / "Ward-2014_Northern_Ireland.csv"
population_filepath_uk = source_files_path / "MYE1-2019.csv"
ward_code_to_la_mapping = {
f["properties"]["WD19CD"]: f["properties"]["LAD19NM"]
for f in geojson.loads(wd_lad_map_filepath.read_text())["features"]
}
ward_code_to_la_id_mapping = {
f["properties"]["WD19CD"]: f["properties"]["LAD19CD"]
for f in geojson.loads(wd_lad_map_filepath.read_text())["features"]
}
# the mapping dict is empty for lower tier local authorities that are also upper tier (unitary authorities, etc)
ltla_utla_mapping_csv = csv.DictReader(ltla_utla_map_filepath.open())
la_code_to_cty_id_mapping = {
row['LTLA19CD']: row['UTLA19CD'] for row in ltla_utla_mapping_csv if row['LTLA19CD'] != row['UTLA19CD']
}
area_to_population_mapping = {}
for population_filepath in (
population_filepath_uk,
population_filepath_england_wales,
population_filepath_northern_ireland,
population_filepath_scotland,
):
area_to_population_csv = csv.DictReader(population_filepath.open())
for row in area_to_population_csv:
area_to_population_mapping[row['ward']] = [
(
int(k) if k.isnumeric() else MEDIAN_AGE_UK,
int(float(v.replace(',', '') or '0'))
)
for k, v in row.items() if k != 'ward'
]
def add_test_areas():
dataset_id = 'test'
dataset_geojson = geojson.loads(test_filepath.read_text())
repo.insert_broadcast_area_library(
dataset_id,
name='Test areas',
name_singular='test area',
is_group=False,
)
areas_to_add = []
for feature in dataset_geojson["features"]:
f_id = feature["properties"]['id']
f_name = feature["properties"]['name']
print() # noqa: T001
print(f_name) # noqa: T001
feature, _, utm_crs = polygons_and_simplified_polygons(
feature["geometry"]
)
areas_to_add.append([
f'{dataset_id}-{f_id}', f_name,
dataset_id, None,
feature, feature,
utm_crs,
0,
])
repo.insert_broadcast_areas(areas_to_add, keep_old_polygons)
def add_countries():
dataset_id = 'ctry19'
dataset_geojson = geojson.loads(ctry19_filepath.read_text())
repo.insert_broadcast_area_library(
'ctry19',
name='Countries',
name_singular='country',
is_group=False,
)
areas_to_add = []
for feature in dataset_geojson["features"]:
f_id = feature["properties"]['ctry19cd']
f_name = feature["properties"]['ctry19nm']
print() # noqa: T001
print(f_name) # noqa: T001
feature, simple_feature, utm_crs = (
polygons_and_simplified_polygons(feature["geometry"])
)
areas_to_add.append([
f'ctry19-{f_id}', f_name,
dataset_id, None,
feature, simple_feature,
utm_crs,
estimate_number_of_smartphones_in_area(f_id),
])
repo.insert_broadcast_areas(areas_to_add, keep_old_polygons)
def add_wards_local_authorities_and_counties():
dataset_name = "Local authorities"
dataset_name_singular = "local authority"
dataset_id = "wd20-lad20-ctyua19"
repo.insert_broadcast_area_library(
dataset_id,
name=dataset_name,
name_singular=dataset_name_singular,
is_group=True,
)
_add_electoral_wards(dataset_id)
_add_local_authorities(dataset_id)
_add_counties_and_unitary_authorities(dataset_id)
def _add_electoral_wards(dataset_id):
areas_to_add = []
for feature in geojson.loads(wd20_filepath.read_text())["features"]:
ward_code = feature["properties"]["wd20cd"]
ward_name = feature["properties"]["wd20nm"]
ward_id = "wd20-" + ward_code
print() # noqa: T001
print(ward_name) # noqa: T001
try:
la_id = "lad20-" + ward_code_to_la_id_mapping[ward_code]
feature, simple_feature, utm_crs = (
polygons_and_simplified_polygons(feature["geometry"])
)
if feature:
rtree_index.insert(ward_id, Rect(*Polygons(feature).bounds))
areas_to_add.append([
ward_id, ward_name,
dataset_id, la_id,
feature, simple_feature,
utm_crs,
estimate_number_of_smartphones_in_area(ward_code),
])
except KeyError:
print("Skipping", ward_code, ward_name) # noqa: T001
rtree_index_path.open('wb').write(pickle.dumps(rtree_index))
repo.insert_broadcast_areas(areas_to_add, keep_old_polygons)
def _add_local_authorities(dataset_id):
areas_to_add = []
for feature in geojson.loads(lad20_filepath.read_text())["features"]:
la_id = feature["properties"]["LAD20CD"]
group_name = feature["properties"]["LAD20NM"]
print() # noqa: T001
print(group_name) # noqa: T001
group_id = "lad20-" + la_id
feature, simple_feature, utm_crs = (
polygons_and_simplified_polygons(feature["geometry"])
)
ctyua_id = la_code_to_cty_id_mapping.get(la_id)
areas_to_add.append([
group_id,
group_name,
dataset_id,
'ctyua19-' + ctyua_id if ctyua_id else None,
feature,
simple_feature,
utm_crs,
None,
])
repo.insert_broadcast_areas(areas_to_add, keep_old_polygons)
# counties and unitary authorities
def _add_counties_and_unitary_authorities(dataset_id):
areas_to_add = []
for feature in geojson.loads(ctyua19_filepath.read_text())['features']:
ctyua_id = feature["properties"]["ctyua19cd"]
group_name = feature["properties"]["ctyua19nm"]
la_id = 'lad20-' + ctyua_id
if repo.get_areas([la_id]):
continue
group_id = "ctyua19-" + ctyua_id
feature, simple_feature, utm_crs = (
polygons_and_simplified_polygons(feature["geometry"])
)
areas_to_add.append([
group_id, group_name,
dataset_id, None,
feature, simple_feature,
utm_crs,
None,
])
repo.insert_broadcast_areas(areas_to_add, keep_old_polygons)
# cheeky global variable
keep_old_polygons = sys.argv[1:] == ['--keep-old-polygons']
print('keep_old_polygons: ', keep_old_polygons) # noqa: T001
repo = BroadcastAreasRepository()
if keep_old_polygons:
repo.delete_library_data()
else:
repo.delete_db()
repo.create_tables()
add_test_areas()
add_countries()
add_wards_local_authorities_and_counties()
most_detailed_polygons = formatted_list(
sorted(point_counts, reverse=True)[:5],
before_each='',
after_each='',
)
print( # noqa: T001
'\n'
'DONE\n'
f' Processed {len(point_counts):,} polygons.\n'
f' Cleaned up {len(invalid_polygons):,} polygons.\n'
f' Highest point counts once simplifed: {most_detailed_polygons}\n'
)