Can I set explicit plot colors for specific values or value ranges

I am creating a sinlge figure output containing multiple plot elements:

surface
contour3
scatter

For the surface plot, if the value is < 1, I want it to plot in green, if the value is >= 1 I want it to plot in blue.

For the contour3 plot, if the value is >= 25, I want it to plot in red

For the scatter plot, I want the default color of blue for the circles.

Is this possible?

Answer 1

[ChristianW]

Yes its possible, only for contour3 its a bit fumbling.

Surface function has an input for the colormatrix C. C is referring to the colormap. Example:

P = peaks;
C(P<1) = 1; % 1 means first color in colormap
C(P>=1) = 2;
C = reshape(C,size(P));
cmap = [0 1 0; 0 0 1]; % check colormap:   colormap(cmap); pcolor(cmap)

figure; surface(peaks,C); view(-35,45)
colormap(cmap)

This contour example checks where the limit value is located in the colormap. Then defining all colors from that location to the end as RED.

figure; contour3(P,40); grid off; view(-25,35)
red_limit = 2;
cmap_contour = jet;
cl = caxis;
I_red = ceil((red_limit-cl(1))/range(cl)*size(cmap_contour,1));

% make colormap from I_red_limit to end all RED
cmap_contour(I_red:end,:) = repmat([1 0 0],size(cmap_contour,1)-I_red+1,1);
colormap(gca,cmap_contour)

In scatter you can define it directly with the markertype input:

scatter(rand(200,1),rand(200,1),'ob') % 'ob' = circle blue

Alternatively you can search the whole figure for circle marker and than make them blue:

figure; hold on; box on
scatter(rand(200,1),rand(200,1),'or')
scatter(rand(200,1),rand(200,1),'ok')
scatter(rand(200,1),rand(200,1),'+r')
figure(gcf); pause(2)
set(findobj(gcf,'Type','Patch','Marker','o'),'MarkerEdgeColor','b')

[Jessica]

Thanks! This is exactly what I needed.

Answer 2

[Amit]

Can you also interpolate the colors in between those stated values? I am struggling with this issue at the moment.