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#!/usr/bin/env python3
# Use the proper idiom in the main module ...
# NOTE: See https://docs.python.org/3.12/library/multiprocessing.html#the-spawn-and-forkserver-start-methods
if __name__ == "__main__":
# Import standard modules ...
import json
import os
# Import special modules ...
try:
import cartopy
cartopy.config.update(
{
"cache_dir" : os.path.expanduser("~/.local/share/cartopy_cache"),
}
)
except:
raise Exception("\"cartopy\" is not installed; run \"pip install --user Cartopy\"") from None
try:
import matplotlib
matplotlib.rcParams.update(
{
"backend" : "Agg", # NOTE: See https://matplotlib.org/stable/gallery/user_interfaces/canvasagg.html
"figure.dpi" : 300,
"figure.figsize" : (9.6, 7.2), # NOTE: See https://github.com/Guymer/misc/blob/main/README.md#matplotlib-figure-sizes
"font.size" : 8,
}
)
import matplotlib.pyplot
except:
raise Exception("\"matplotlib\" is not installed; run \"pip install --user matplotlib\"") from None
try:
import shapely
import shapely.geometry
import shapely.ops
except:
raise Exception("\"shapely\" is not installed; run \"pip install --user Shapely\"") from None
# Import my modules ...
try:
import fmc
except:
raise Exception("\"fmc\" is not installed; run \"pip install --user git+https://github.com/Guymer/fmc.git\"") from None
try:
import pyguymer3
import pyguymer3.geo
import pyguymer3.image
except:
raise Exception("\"pyguymer3\" is not installed; run \"pip install --user PyGuymer3\"") from None
# **************************************************************************
# Create short-hand for the colour map and define the nautical mile ...
cmap = matplotlib.colormaps["turbo"]
nm = 1852.0 # [m/NM]
# **************************************************************************
# Create a list of ISO 3166-1 Alpha-3 codes of British Overseas Territories
# (see "ISO 3166-1.json" in my "misc" repository for the complete list) ...
a3s = [
"AIA", # Anguilla
"BMU", # Bermuda
"CYM", # Cayman Islands (the)
"FLK", # Falkland Islands (the)
"GBR", # United Kingdom of Great Britain and Northern Ireland (the)
"GIB", # Gibraltar
"IOT", # British Indian Ocean Territory (the)
"MSR", # Montserrat
"PCN", # Pitcairn
"SGS", # South Georgia and the South Sandwich Islands
"SHN", # Saint Helena, Ascension and Tristan da Cunha
"TCA", # Turks and Caicos Islands (the)
"VGB", # Virgin Islands (British)
]
# Load airport list ...
with open(f"{fmc.__path__[0]}/db.json", "rt", encoding = "utf-8") as fObj:
airports = json.load(fObj)
# Create list of British airfields (manually adding LCRA as it is marked as
# being part of Cyprus in the OurAirports Data GitHub repository) ...
airfields = [] # [°], [°]
for airport in airports:
if "lon" not in airport or "lat" not in airport:
continue
if "ICAO" in airport:
if airport["ICAO"] == "LCRA":
pnt = shapely.geometry.Point(airport["lon"], airport["lat"]) # [°], [°]
airfields.append(pnt) # [°], [°]
continue
if "ISO 3166-1 Alpha-3" in airport:
if airport["ISO 3166-1 Alpha-3"] in a3s:
pnt = shapely.geometry.Point(airport["lon"], airport["lat"]) # [°], [°]
airfields.append(pnt) # [°], [°]
continue
print(f"There are {len(airfields):d} British airfields.")
# **************************************************************************
# Create figure ...
fg = matplotlib.pyplot.figure(figsize = (12.8, 7.2))
# Create axis ...
ax = pyguymer3.geo.add_axis(
fg,
add_coastlines = False,
add_gridlines = False,
debug = False,
nIter = 100,
onlyValid = False,
repair = False,
)
# Configure axis ...
pyguymer3.geo.add_map_background(
ax,
debug = False,
resolution = "large8192px",
)
# Add country outlines ...
for record in cartopy.io.shapereader.Reader(
cartopy.io.shapereader.natural_earth(
category = "cultural",
name = "admin_0_countries",
resolution = "10m",
)
).records():
ax.add_geometries(
pyguymer3.geo.extract_polys(
record.geometry,
onlyValid = False,
repair = False,
),
cartopy.crs.PlateCarree(),
edgecolor = "black",
facecolor = "none",
linewidth = 0.5,
)
# Initialize distance, labels and lines ...
dist2 = 0.0 # [NM]
labels = []
lines = []
# Loop over distances ...
for i in range(8):
# Set distance ...
dist1 = 500.0 # [NM]
dist2 += dist1 # [NM]
# Decide what needs doing ...
if i == 0:
print(f"Calculating for {dist2:6,.0f} NM (using {len(airfields):,d} airfields) ...")
# Buffer airfields ...
# NOTE: "airfields" is the Point-list to be buffered.
geoms = []
for airfield in airfields:
geoms += pyguymer3.geo.extract_polys(
pyguymer3.geo.buffer(
airfield,
dist1 * nm,
debug = False,
fill = 0.1,
fillSpace = "EuclideanSpace",
keepInteriors = True,
nAng = 361,
nIter = 100,
simp = 0.01,
),
onlyValid = False,
repair = False,
)
geoms = shapely.ops.unary_union(geoms).simplify(1.0e-10)
pyguymer3.geo.check(geoms)
# NOTE: "geoms" is now the [Multi]Polygon buffer of "airfields".
else:
# Find out how complicated the [Multi]Polygon is ...
npoints = 0 # [#]
npolys = 0 # [#]
for poly in pyguymer3.geo.extract_polys(
geoms,
onlyValid = False,
repair = False,
):
npoints += len(poly.exterior.coords) # [#]
npolys += 1 # [#]
for interior in poly.interiors:
npoints += len(interior.coords) # [#]
print(f"Calculating for {dist2:6,.0f} NM (using {npoints:,d} points in {npolys:,d} Polygons) ...")
# Buffer area ...
# NOTE: "geoms" is the [Multi]Polygon to be buffered.
geoms = pyguymer3.geo.buffer(
geoms,
dist1 * nm,
debug = False,
fill = 0.1,
fillSpace = "EuclideanSpace",
keepInteriors = True,
nAng = 361,
nIter = 100,
simp = 0.01,
)
# NOTE: "geoms" is now the [Multi]Polygon buffer of "geoms".
# Add to plot ...
ax.add_geometries(
pyguymer3.geo.extract_polys(
geoms,
onlyValid = False,
repair = False,
),
cartopy.crs.PlateCarree(),
edgecolor = cmap(float(i) / 7.0),
facecolor = "none",
linewidth = 1.0,
)
labels.append(f"{dist2:6,.0f} NM")
lines.append(matplotlib.lines.Line2D([], [], color = cmap(float(i) / 7.0)))
print("Plotting ...")
# Configure axis ...
ax.legend(
lines,
labels,
loc = "upper center",
ncol = 4,
)
# Configure figure ...
fg.tight_layout()
# Save figure ...
fg.savefig("find_airfields.png")
matplotlib.pyplot.close(fg)
# Optimize PNG ...
pyguymer3.image.optimise_image(
"find_airfields.png",
debug = False,
strip = True,
timeout = 60.0,
)
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