Como faço para desenhar uma elipse shapely?
8
Primeiro, defina um círculo de raio 1.
Em seguida, defina uma elipse ao longo dos eixos x e y.
Por fim, gire a elipse.
EDIT: Finalmente, realmente desenhe a elipse
EDIT: elipse definido anteriormente pelo código, mas não desenhou nada como solicitado
from matplotlib import pyplot
from shapely.geometry.point import Point
import shapely.affinity
from descartes import PolygonPatch
# Note: download figures.py manually from shapely github repo, put it in shapely install directory
from shapely.figures import SIZE, GREEN, GRAY, set_limits
# 1st elem = center point (x,y) coordinates
# 2nd elem = the two semi-axis values (along x, along y)
# 3rd elem = angle in degrees between x-axis of the Cartesian base
# and the corresponding semi-axis
ellipse = ((0, 0),(7, 4),36)
# Let create a circle of radius 1 around center point:
circ = shapely.geometry.Point(ellipse[0]).buffer(1)
# Let create the ellipse along x and y:
ell = shapely.affinity.scale(circ, int(ellipse[1][0]), int(ellipse[1][1]))
# Let rotate the ellipse (clockwise, x axis pointing right):
ellr = shapely.affinity.rotate(ell,ellipse[2])
# If one need to rotate it clockwise along an upward pointing x axis:
elrv = shapely.affinity.rotate(ell,90-ellipse[2])
# According to the man, a positive value means a anti-clockwise angle,
# and a negative one a clockwise angle.
fig = pyplot.figure()
ax = fig.add_subplot(111)
patch = PolygonPatch(elrv, fc=GREEN, ec=GRAY, alpha=0.5, zorder=2)
ax.add_patch(patch)
set_limits(ax, -10, 10, -10, 10)
pyplot.show()Documentação bem torneada:
http://toblerity.org/shapely/manual.html
É isso aí!
Resultado de elrv:
