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misc example code: contour_manual.pyΒΆ

[source code]

"""
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)