2d hsv color space in matplotlib

Question

I am trying to reproduce this graph in matplotlib (taken from wikipedia)

basically 2d hsv color space, where saturation is set to 1.0. that's what i have done so far

from pylab import * from numpy import outer x = outer(arange(0, 1, 0.01), ones(100)) imshow(transpose(x), cmap=cm.hsv) show() 

this displays a hue channel, but I don’t know how to add a second channel.

Answer 1

You need to create an HSV array and convert it to RGB, here is an example:

 import numpy as np import pylab as pl from matplotlib.colors import hsv_to_rgb V, H = np.mgrid[0:1:100j, 0:1:300j] S = np.ones_like(V) HSV = np.dstack((H,S,V)) RGB = hsv_to_rgb(HSV) pl.imshow(RGB, origin="lower", extent=[0, 360, 0, 1], aspect=150) pl.xlabel("H") pl.ylabel("V") pl.title("$S_{HSV}=1$") pl.show() 

output: