"""
Example of displaying your own contour lines and polygons using ContourSet.
"""
import matplotlib.pyplot as plt
from matplotlib.contour import ContourSet
import matplotlib.cm as cm
# Contour lines for each level are a list/tuple of polygons.
lines0 = [[[0, 0], [0, 4]]]
lines1 = [[[2, 0], [1, 2], [1, 3]]]
lines2 = [[[3, 0], [3, 2]], [[3, 3], [3, 4]]] # Note two lines.
# Filled contours between two levels are also a list/tuple of polygons.
# Points can be ordered clockwise or anticlockwise.
filled01 = [[[0, 0], [0, 4], [1, 3], [1, 2], [2, 0]]]
filled12 = [[[2, 0], [3, 0], [3, 2], [1, 3], [1, 2]], # Note two polygons.
[[1, 4], [3, 4], [3, 3]]]
plt.figure()
# Filled contours using filled=True.
cs = ContourSet(plt.gca(), [0, 1, 2], [filled01, filled12], filled=True, cmap=cm.bone)
cbar = plt.colorbar(cs)
# Contour lines (non-filled).
lines = ContourSet(plt.gca(), [0, 1, 2], [lines0, lines1, lines2], cmap=cm.cool,
linewidths=3)
cbar.add_lines(lines)
plt.axis([-0.5, 3.5, -0.5, 4.5])
plt.title('User-specified contours')
# Multiple filled contour lines can be specified in a single list of polygon
# vertices along with a list of vertex kinds (code types) as described in the
# Path class. This is particularly useful for polygons with holes.
# Here a code type of 1 is a MOVETO, and 2 is a LINETO.
plt.figure()
filled01 = [[[0, 0], [3, 0], [3, 3], [0, 3], [1, 1], [1, 2], [2, 2], [2, 1]]]
kinds01 = [[1, 2, 2, 2, 1, 2, 2, 2]]
cs = ContourSet(plt.gca(), [0, 1], [filled01], [kinds01], filled=True)
cbar = plt.colorbar(cs)
plt.axis([-0.5, 3.5, -0.5, 3.5])
plt.title('User specified filled contours with holes')
plt.show()
Keywords: python, matplotlib, pylab, example, codex (see Search examples)