plot3 Not Animating with the Loop (Drawnow is already added)

The 3D line is drawn with the mtm_x matrix set (3*2*100). In each loop, a set of 3*2 matrix is used to update the values of the line.

I checked that the values of Tip0 and TipX are updating. But the line stays in the initial position. (I've varied the loop no., but the line just stays there......)

Any suggestion?

mtm_x = mtm_x(:,:,1:100); % mtm_x is imported and become a 3*2*100 double

nt = length(mtm_x); % nt = 100
s=0.25;

figure(2);
grid on;
view(3);

for i = 1:nt
cla;
tip_x = mtm_x(:,:,i); % the 3D line is updated with i-th value set. e.g. for i=1, the first 3*2 matrix is used 
%tip
TipO = tip_x(1:3,2);
TipX = tip_x(1:3,1).*s; 
plot3([TipO(1) TipX(1)+TipO(1)], [TipO(2) TipX(2)+TipO(2)], [TipO(3) TipX(3)+TipO(3)], 'color', 'r', 'linewidth', 3);
hold on
axis([-0.5 0.5 -0.5 0.5 -0.5 0.5]);
drawnow;
end

Thanks!

[Aquatris]

The problem might be it actually animates but does it so fast you do not see it. Try adding a pause after axis command. To do that add the following code after "axis" line;

pause(0.001)

[Jan]

@Aqutris: :-) It will be hard to see a delay of a millisecond, when the monitor is updated with 60Hz. A longer pause would be useful.

[Laurel Castillo]

Yeah, you're right! It's too fast to see! Thanks!

Answer 1

[Jan]

mtm_x = rand(3,2,100); % mtm_x is imported and become a 3*2*100 double
nt    = size(mtm_x, 3); % do not rely on LENGTH
s     = 0.25;
Lim   = [0, 1];
axesH = axes('XLim', Lim, 'YLim', Lim, 'ZLim', Lim, ...
    'NextPlot', 'add');
grid on;
view(3);

for i = 1:nt
  tip_x = mtm_x(:,:,i);
  TipO  = tip_x(1:3,2);
  TipX  = tip_x(1:3,1) .* s; 
  plot3(axesH, ...
        [TipO(1) TipX(1)+TipO(1)], ...
        [TipO(2) TipX(2)+TipO(2)], ...
        [TipO(3) TipX(3)+TipO(3)], ...
        'color', 'r', 'linewidth', 3);
  drawnow;
end

This is a cleaned version without the cla . I can see a bunch of lines. So what exactly is the problem?

Where do you try to display this? I do not see the intermediate images in Matlab online.

[Laurel Castillo]

Thanks!