In [1]:
from Circles.circles import circle
from mpl_toolkits.basemap import Basemap
import matplotlib.pyplot as plt
from matplotlib.collections import PatchCollection
from shapely.geometry import Polygon, MultiPolygon, Point
from descartes import PolygonPatch
import numpy as np
%matplotlib inline
In [2]:
from matplotlib import rc
rc('font', **{'family':'sans-serif',
'sans-serif':['Helvetica'],
'monospace': ['Inconsolata'],
'serif': ['Helvetica']})
rc('text', **{'usetex': True})
rc('text', **{'latex.preamble': '\usepackage{sfmath}'})
In [3]:
# use the Robinson projection - it'll distort nicely
m = Basemap(resolution='i', projection='robin', lon_0=0)
In [4]:
# let's calculate a 2584-km circle
RADIUS = 2584
centerlon = 0.135875
centerlat = 51.5219198
coords = circle(m, centerlon, centerlat, RADIUS)
casa = Polygon(coords)
In [5]:
# let's do the same with a circle calculated in cartesian coordinates
# http://mitpress.mit.edu/books/road-not-road-and-open-city-ritoque-chile
rlon = -71.530303
rlat = -32.824977
p = Point(m(rlon, rlat))
ritoque = p.buffer(RADIUS * 1000)
# now let's calculate it correctly
ritoque_correct = Polygon(circle(m, rlon, rlat, RADIUS))
In [6]:
# let's calculate a series of concentric circles originating in Perth
plon = 115.9313409
plat = -31.9688837
radii = [144, 233, 377, 610, 987, 1597, 2584, 4181]
e_coords = [circle(m, plon, plat, fib) for fib in radii]
perth = [Polygon(coord) for coord in e_coords]
In [12]:
# let's plot everything
plt.clf()
fig = plt.figure()
ax = fig.add_subplot(111, axisbg='w', frame_on=False)
cpatch = PolygonPatch(casa, fc='#33CCFF', ec='#000000', lw=.5, alpha=.75, zorder=2)
rpatch = PolygonPatch(ritoque, fc='none', ec='#333333', lw=0, ls='dotted', hatch='....', zorder=1)
rpatch_correct = PolygonPatch(ritoque_correct, fc='#CC00CC', ec='#000000', lw=.5, alpha=.75, zorder=2)
# the concentric circles are treated as a PatchCollection
ppatch = PatchCollection(
[PolygonPatch(poly) for poly in perth],
color='none', edgecolor='#ff0000', lw=0.85, alpha=0.75, zorder=3)
# draw map features
m.drawmapboundary(fill_color='none', linewidth=0.25, zorder=0)
# m.drawcountries(linewidth=.25, color='#000000', zorder=2)
m.drawcoastlines(linewidth=.5, zorder=1)
m.fillcontinents(color='#555555', lake_color='#555555', zorder=1)
# m.drawparallels(np.arange(-90., 120., 30.), alpha=0.5, lw=0.25, zorder=1)
# m.drawmeridians(np.arange(0., 360., 60.), alpha=0.5, lw=0.25, zorder=1)
# draw circles
ax.add_patch(cpatch)
ax.add_patch(rpatch)
ax.add_patch(rpatch_correct)
ax.add_collection(ppatch)
# draw great circles - note perth --> ritoque is correct as of Basemap v1.0.8
m.drawgreatcircle(rlon, rlat, centerlon, centerlat, lw=1.75, color='#FFCC00', zorder=1)
m.drawgreatcircle(centerlon, centerlat, plon, plat, lw=1.75, color='#FFCC00', zorder=1)
m.drawgreatcircle(plon, plat, rlon, rlat, lw=1.75, color='#FFCC00', zorder=1)
# with apologies to Sugababes
plt.title("Like a Circle in a Spiral")
plt.tight_layout()
fig.set_size_inches(7.28, 5.5)
# plt.savefig('circles.png', alpha=True)
plt.savefig("circles.png", format="png", bbox_inches='tight', transparent=True, dpi=300)
plt.show()
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