Colormap and plot with nxn matrices

Hi,

I have got 2 matrices x and y. For each x(i,:) y(i,:) I have got an array z. Now I want to draw them color coded like in a scatter plot corresponding with z and I also also want to have a colorbar, which is linked to the according color. At the same moment I want to have a solid line connecting the points in one course x(i,:) y(i,:).

Answer 1

[Kelly Kearney]

You can use a patch to make a color-changing line:

 x = rand(10,1);
 y = rand(10,1);
 z = rand(10,1);
 hp = patch([x' NaN], [y' NaN], 0);
 set(hp,'cdata', [z' NaN], 'edgecolor','interp','facecolor','none');
 hold on;
 scatter(x,y,20,z,'filled');

[betlor5]

Ok, but I still can't set the patch to a pre defined colormap or can I?

[Kelly Kearney]

The patch will follow the same colormap as the scatter plot, and you can change both the colormap and color limits for the axis to be whatever you need it to be.

Answer 2

[Walter Roberson]

for K = 1:size(x,1)
  plot(x(K,:),y(K,:),'-');  %solid line, no marker
  hold on
  pointsize = 8;  %adjust as needed
  scatter(x(K,:),y(K,:),pointsize,z(K,:));  %color coded dots
end
colorbar

[betlor5]

But that wouldn't change the color of the solid line. It would still be the defailt color, wouldn't it?

[Walter Roberson]

Yup. You didn't say you wanted to color-code the line itself.

There is no way built in to MATLAB to have a "line" or "lineseries" object have more than one color, so you need to color each segment individually.

Please indicate what color you expect each segment on the line to be. What about the segments that go between z of different value?

[betlor5]

I have got multiple lines expressed through the points in my matrices x and y. These lines are independent from each other. Therefor I want to draw each line in one color corresponding to the z value. Let's say I want to display the x(1,:), y(1,:) curve. This curve shall be plottet in the color of z(1). And the colors of z shall follow a colormap, for example jet.