heatmap_triangle

def pcolormesh_45deg(matrix_c, ax, start=0, resolution=1, *args, **kwargs):
    start_pos_vector = [start+resolution*i for i in range(len(matrix_c)+1)]
    import itertools
    n = matrix_c.shape[0]
    t = np.array([[1, 0.5], [-1, 0.5]])
    matrix_a = np.dot(np.array([(i[1], i[0])
                                for i in itertools.product(start_pos_vector[::-1],
                                                           start_pos_vector)]), t)
    x = matrix_a[:, 1].reshape(n + 1, n + 1)
    y = matrix_a[:, 0].reshape(n + 1, n + 1)
    im = ax.pcolormesh(x, y, np.flipud(matrix_c), *args, **kwargs)
    im.set_rasterized(True)
    return im