There are two issues with your code:
- You are calling patch repeatedly, which is adding a new patch in each loop, without removing the old patches, so the patches are overlapping one another. This isn't really causing an issue, but it is not very efficient, and could easily cause issues in the future or with different animations.
- You are not fixing the color limits, which means that each time the loop runs it is picking color limits to tightly crop the data. This is the real reason you only see the colorbar changing on each loop.
The quickest fix to your code is to call clim (or previously called caxis) before your loop, or within your loop, to fix the color imits at a single value.
clim([0 0.0639])
But, you really want to be more efficient with your patches:
- Either delete the old patches each loop before creating new ones.
- But even better is reusing the patches each loop.
For example:
STEPS = 40;
q = zeros(14,STEPS);
q(:,1) = [0;0;0;0;0;0;0;0;0;0;0;0;0;0];
q(:,2) = [0;0;0.01;0.001;0.01;0.001;0;0;0.0025;0.00025;0.0025;0.00025;0.005;0];
for i = 3 : STEPS
q(:,i) = q(:,i-1) * 1.05;
end%for
RGB = [0 0 1
0 0.5 1
0 1 1
0 1 0.5
0 1 0
0.5 1 0
1 1 0
1 0.5 0
1 0 0];
Q = q(:,STEPS);
Q = Q(1:2:end);
% data for patch
msh_1.nn_3sz = [3,2,7;2,6,7;5,3,7;6,5,7];
msh_1.nn_4sz = [5,4,1,6];
msh_1.xy = [0,0;2,0;2,1;0,1;1,1;1,0;1.5,0.5];
figure (8)
qxy="qx";
% Create two patches that can be reused.
p1 = patch();
p2 = patch();
% Do one-time configuration of the axes and figure
set(gcf, 'color', 'w')
colormap(RGB);
colorbar('EastOutside')
axis equal
% Fix the color limits
clim([0 0.0639])
for i = 1:STEPS
Q = q(:,i);
QX = Q(1:2:size(Q,1)-1);
QY = Q(2:2:size(Q,1));
switch qxy % displacements in X and Y dimensions
case "qx"
QQ = QX;
case "qy"
QQ = QY;
case "q"
QQ = sqrt(QX.^2+QY.^2);
end%switch
% Reuse/update the existing patches with the new data:
set(p1, 'Faces',msh_1.nn_3sz,'Vertices', msh_1.xy,'FaceVertexCData',QQ,'FaceColor','interp')
set(p2, 'Faces',msh_1.nn_4sz,'Vertices', msh_1.xy,'FaceVertexCData',QQ,'FaceColor','interp')
drawnow()
end %for
