Re: [Matplotlib-users] Confused about rgb_to_hsv and hsv_to_rgb

[Eric F. <ef...@ha...>]

On 2015/05/21 11:28 AM, Matteo Niccoli wrote:
> OK, I understand.
>
>
> Could you suggest a way to reduce that 3D array to a 2D array and plot it
> with a specific colormap, while preserving the shading?

It looks like you will get what you want by following the titusjan's 
advice in his reply.  If you are not seeing a shaded version of 
cubehelix, then the only thing I can imagine is that you inadvertently 
omitted the second line in his example:

  img_array = plt.get_cmap('cubehelix')(data_n)

This is doing the colormapping at the start, generating the 3D array 
that you modify to apply your shading algorithm.

Eric