.. _misc-contour_manual:

misc example code: contour_manual.py
====================================

[`source code <contour_manual.py>`_]

::

    """
    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 :ref:`how-to-search-examples`)