How can I add colors on my 3D scatter plot ?

Hi,

I have three vectors (listeX, listeY, listeCycles). I want to plot using scatter3() function.

It results in this chart:

I would like to color in different colors the points on the vertical axis Z, according to their Z-coordinate.

For instance, having red for the bottom data, green for medium and blue for the data above.

Here is my code . Thank you very much !

figure
scatter3(listeX,listeY,listeCycles,'MarkerEdgeColor','k','MarkerFaceColor',[0 .75 .75])
xlabel('Temps ouverture minimum (s)');
ylabel('deadband (°)');
zlabel('Nombre de cycles sur projection 10 000s');

Answer 1

[Adam Danz]

Specify color from scatter3()

You can specify the color of each point when you call scatter3(X,Y,Z,S,C) or by using the property-value, scatter3(X,Y,Z,. . .,'MarkerFaceColor',C) where C is an n-by-3 matrix of RGB value, one row for each point.

Specify color using the scatter object handle

Alternatively, you can specify the color after plotting by setting the CData property as an n-by-3 matrix of RGB values.

h = scatter3(. . ., 'filled'); 
h.CData = C; 

Creating the RGB matrix

One simple way to create the RGB color matrix is to use one of Matlab's colormaps and specify the number of points. This example uses jet and inputs the number of values in the first input to scatter3, X. See this list for other built-in colormaps.

C = jet(numel(X));

To add a colobar,

set(gca, 'colormap', C)
colorbar()

Full Demo

figure
[X,Y,Z] = sphere(16);
x = [0.5*X(:); 0.75*X(:); X(:)];
y = [0.5*Y(:); 0.75*Y(:); Y(:)];
z = [0.5*Z(:); 0.75*Z(:); Z(:)];
h = scatter3(x,y,z,'filled','MarkerEdgeColor','k');
axis equal
box on
C = jet(numel(x));
h.CData = C
set(gca, 'colormap', C)
colorbar()

[Louis THOMAS]

Thank you !

the problem now is that the command h.CData=C; does not have any impact on my chart colors ...

figure
C=jet(numel(listeX2));
h=scatter3(listeX2,listeY,listeCycles,'MarkerEdgeColor','k','MarkerFaceColor',[0 .75 .75]);
h.CData = C;
xlabel('Temps ouverture minimum (s)');
ylabel('deadband (°)');
zlabel('Nombre de cycles sur projection 10 000s');
view(-30,10)

[Adam Danz]

Try removing MarkerFaceColor and adding filled.

h=scatter3(listeX2,listeY,listeCycles,'filled','MarkerEdgeColor','k');
h.CData = C;

Here's a functional demo

figure
[X,Y,Z] = sphere(16);
x = [0.5*X(:); 0.75*X(:); X(:)];
y = [0.5*Y(:); 0.75*Y(:); Y(:)];
z = [0.5*Z(:); 0.75*Z(:); Z(:)];

h = scatter3(x,y,z,'filled','MarkerEdgeColor','k');
axis equal

C = jet(numel(x));
h.CData = C

[Louis THOMAS]

Works perfectly thank you very much!

[Dipali Ghodake]

How to show colormap to this plot?

[Adam Danz]

set(gca, 'Colormap', C)
colorbar()