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axes_grid example code: demo_axes_rgb.pyΒΆ

(Source code)

import numpy as np
import matplotlib.pyplot as plt

from mpl_toolkits.axes_grid1.axes_rgb import make_rgb_axes, RGBAxes

def get_demo_image():
    from matplotlib.cbook import get_sample_data
    f = get_sample_data("axes_grid/bivariate_normal.npy", asfileobj=False)
    z = np.load(f)
    # z is a numpy array of 15x15
    return z, (-3,4,-4,3)

def get_rgb():
    Z, extent = get_demo_image()

    Z[Z<0] = 0.
    Z = Z/Z.max()

    R = Z[:13,:13]
    G = Z[2:,2:]
    B = Z[:13,2:]

    return R, G, B

def make_cube(r, g, b):
    ny, nx = r.shape
    R = np.zeros([ny, nx, 3], dtype="d")
    R[:,:,0] = r
    G = np.zeros_like(R)
    G[:,:,1] = g
    B = np.zeros_like(R)
    B[:,:,2] = b

    RGB = R + G + B

    return R, G, B, RGB

def demo_rgb():
    fig, ax = plt.subplots()
    ax_r, ax_g, ax_b = make_rgb_axes(ax, pad=0.02)

    r, g, b = get_rgb()
    im_r, im_g, im_b, im_rgb = make_cube(r, g, b)
    kwargs = dict(origin="lower", interpolation="nearest")
    ax.imshow(im_rgb, **kwargs)
    ax_r.imshow(im_r, **kwargs)
    ax_g.imshow(im_g, **kwargs)
    ax_b.imshow(im_b, **kwargs)

def demo_rgb2():
    fig = plt.figure(2)
    ax = RGBAxes(fig, [0.1, 0.1, 0.8, 0.8], pad=0.0)

    r, g, b = get_rgb()
    kwargs = dict(origin="lower", interpolation="nearest")
    ax.imshow_rgb(r, g, b, **kwargs)

    ax.RGB.set_xlim(0., 9.5)
    ax.RGB.set_ylim(0.9, 10.6)

    for ax1 in [ax.RGB, ax.R, ax.G, ax.B]:
        for sp1 in ax1.spines.values():
        for tick in ax1.xaxis.get_major_ticks() + ax1.yaxis.get_major_ticks():

    return ax

ax = demo_rgb2()

Keywords: python, matplotlib, pylab, example, codex (see Search examples)