matplotlib like color spy

cspy.py

def fastspy(A, ax, cmap=None):
    """"
    Parameters
    ----------
    A : coo matrix

    ax : axis

    """

    m, n = A.shape
    ax.hold(True)

    ax.scatter(A.row, A.col, c=A.data, s=20, marker='s',
               edgecolors='none', clip_on=False,
               cmap=cmap)

    ax.axis('off')
    ax.axis('tight')
    ax.invert_yaxis()
    ax.hold(False)

if __name__ == '__main__':
    import scipy.io as io
    import matplotlib.pyplot as plt
    A = io.loadmat('example.mat')['A'].tocoo()
    fig = plt.figure()
    ax = fig.add_subplot(111)
    fastspy(A, ax)
    plt.show()

example.mat