Get the facecolor of a contourf plot

I would like to find the facecolor of the the contourf patches. For example if :

[X,Y,Z] = peaks;
figure
contourf(X,Y,Z,4)

I would like to get the 5 different facecolors of the patches of the contour.

Thank you

Answer 1

[Doug Hull]

[X,Y,Z] = peaks;
[l, h] = contourf(X,Y,Z,4)
hp = get(h,'children')
get(hp,'cdata')
colorbar

This gets you the value of the cdata. Look at the colormap to get the actual RGB color. Look at the colorbar to see what those values correspond to.

[Giorgos Papakonstantinou]

Thank you Doug! But is there any way to get the color codes of those colors? So,get a matrix 5x3?

[Kelly Kearney]

I wrote a function that extracts this sort of data from a colormap: interpcolor

[X,Y,Z] = peaks;
[l, h] = contourf(X,Y,Z,4);
hp = get(h,'children');
colorbar;

clim = get(gca, 'clim');
cdata = cell2mat(get(hp, 'cdata'));
cmap = colormap;  

col = interpcolor(cdata, cmap, clim)

---

col =

            1      0.48437            0
          0.5            0            0
            0            0       0.5625
            0      0.54688            1
            0      0.54688            1
            1      0.48437            0
      0.53125            1      0.46875
            0      0.54688            1
            0            0       0.5625

[Kellen]

Any ideas on how to do this in 2014b, in which the cdata field no longer exists?

[Kelly Kearney]

On the plus side, the new version stores the exact color value, so you don't need to use the color interpolation trick. On the down side, the properties are buried under a few layers of undocumented properties, so this may change down the road:

[X,Y,Z] = peaks;
[l, h] = contourf(X,Y,Z,4);
rgba = double(cat(2, h.FacePrims.ColorData))./255;
col = rgba(1:3,:)';

[Johannes Korsawe]

Kelly, is there some undocumented chance for some magic to set some FaceAlpha-Values for the plotted areas of the contourf-command?