.. _frontpage-plot_contour:

frontpage example code: plot_contour.py
=======================================

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

::

    """
    =========================
    Frontpage contour example
    =========================
    
    This example reproduces the frontpage contour example.
    """
    
    import matplotlib.pyplot as plt
    import numpy as np
    from matplotlib import mlab, cm
    
    extent = (-3, 3, -3, 3)
    
    delta = 0.5
    x = np.arange(-3.0, 4.001, delta)
    y = np.arange(-4.0, 3.001, delta)
    X, Y = np.meshgrid(x, y)
    Z1 = mlab.bivariate_normal(X, Y, 1.0, 1.0, 0.0, -0.5)
    Z2 = mlab.bivariate_normal(X, Y, 1.5, 0.5, 1, 1)
    Z = (Z1 - Z2) * 10
    
    levels = np.linspace(-2.0, 1.601, 40)
    norm = cm.colors.Normalize(vmax=abs(Z).max(), vmin=-abs(Z).max())
    
    fig, ax = plt.subplots()
    cset1 = ax.contourf(
        X, Y, Z, levels,
        norm=norm)
    ax.set_xlim(-3, 3)
    ax.set_ylim(-3, 3)
    ax.set_xticks([])
    ax.set_yticks([])
    fig.savefig("contour_frontpage.png", dpi=25)  # results in 160x120 px image
    

Keywords: python, matplotlib, pylab, example, codex (see :ref:`how-to-search-examples`)