You are reading an old version of the documentation (v2.1.0). For the latest version see https://matplotlib.org/stable/gallery/misc/contour_manual.html
matplotlib
Fork me on GitHub


Travis-CI:

Related Topics

This Page

Manual ContourΒΆ

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')
../../_images/sphx_glr_contour_manual_001.png

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()
../../_images/sphx_glr_contour_manual_002.png

Total running time of the script: ( 0 minutes 0.077 seconds)

Gallery generated by Sphinx-Gallery