Initialize to Increase Efficiency of plot3 Animation in Loop

One line is stationary. The moving line is drawn with the psm_xp1V set (4*4*10). In each loop, a set of 4*4 matrix is used to update the values of the line.

Here is my main. Basically I just load the data and put the animiation function in the loop.

psm_xp1V_data = load ('psm_xp1V.mat', 'psm_xp1V');
for i=1:10
    psm_xp1V=psm_xp1V_data.psm_xp1V(:,:,i);
    [frame_plot] = animation3(psm_xp1V);
end

The animatioin function. The Base line is constant. And the Tip line updates in each loop, according to the dataset.

function [frame_plot]=animation3(psm_xp1V)

figure(3); % BTW I added these two lines here to make the figure as an output of the function. Do I really have to do so?
frame_plot = figure(3); %
axis([-0.5 0.5 -0.5 0.5 -0.5 0.5]);
grid on;
view(3);
s=0.1;
cla;

%Base
Base = eye(4);
BaseO = Base(1:3,4);
BaseX = Base(1:3,1).*s; 
plot3([BaseO(1) BaseX(1)+BaseO(1)], [BaseO(2) BaseX(2)+BaseO(2)], [BaseO(3) BaseX(3)+BaseO(3)], ...
    'color', 'r', 'linewidth', 3);
hold on % And do I really need hold on?

%Tip
tip_x = psm_xp1V; %input
TipO = tip_x(1:3,4);
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

drawnow;
end

Can I increase the efficiency by adding another function to initialize the figure before the loop?

So we don't have to create and update the whole figure in each loop. Maybe just update the values for the moving line Tip in each loop.

Please advise.

Answer 1

[Steven Lord]

Don't call plot3 over and over, which will keep increasing the number of graphics objects present in the figure. Instead either use the animatedline function or use one of the techniques described in the "Animation Techniques" section on this documentation page.

[Laurel Castillo]

Thanks for your feedback!

I replace plot3 with animatedline and it works.

%tip
tip_x = psm_xp1V; %input
h = animatedline;
TipO = tip_x(1:3,4);
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);
addpoints(h,[TipO(1) TipX(1)+TipO(1)],[TipO(2) TipX(2)+TipO(2)],[TipO(3) TipX(3)+TipO(3)]);
%hold on

But still the whole function runs once in each loop. Is it possible to extract parts of the codes before the loop?

Like these parts, which are not changed in each loop but they are in the plot:

axis([-0.5 0.5 -0.5 0.5 -0.5 0.5]);
grid on;
view(3);
s=0.1;
cla;
%Base
Base = eye(4);
BaseO = Base(1:3,4);
BaseX = Base(1:3,1).*s; 
plot3([BaseO(1) BaseX(1)+BaseO(1)], [BaseO(2) BaseX(2)+BaseO(2)], [BaseO(3) BaseX(3)+BaseO(3)], ...
    'color', 'r', 'linewidth', 3);
hold on % And do I really need hold on?

Or, it is necesaary to do so?

[Laurel Castillo]

An update!

I managed to modify it into this, extracting the stationary parts out of the loop.

But I am not able to turn the plotting part in the loop to a function.......

psm_xp1V_data = load ('psm_xp1V.mat', 'psm_xp1V');
s=0.1;
axis([-0.5 0.5 -0.5 0.5 -0.5 0.5]);
grid on;
view(3);
Base = eye(4);
BaseO = Base(1:3,4);
BaseX = Base(1:3,1).*s; 
bx = animatedline([BaseO(1) BaseX(1)+BaseO(1)],[BaseO(2) BaseX(2)+BaseO(2)],[BaseO(3) BaseX(3)+BaseO(3)], 'Color', 'r','linewidth', 3);
tx = animatedline('MaximumNumPoints',2,'Color', 'r','linewidth', 3);

for i=1:10
    psm_xp1V=psm_xp1V_data.psm_xp1V(:,:,i);
%     cla;
    TipO = psm_xp1V(1:3,4);
    TipX = psm_xp1V(1:3,1).*s; 
    addpoints(tx,[TipO(1) TipX(1)+TipO(1)],[TipO(2) TipX(2)+TipO(2)],[TipO(3) TipX(3)+TipO(3)]);

    drawnow;

end

[Laurel Castillo]

OK! Turned the animation part into a function! Any advise to speed it up further?

psm_xp1V_data = load ('psm_xp1V.mat', 'psm_xp1V');
s=0.1;
axis([-0.5 0.5 -0.5 0.5 -0.5 0.5]);
grid on;
view(3);
Base = eye(4);
BaseO = Base(1:3,4);
BaseX = Base(1:3,1).*s; 
bx = animatedline([BaseO(1) BaseX(1)+BaseO(1)],[BaseO(2) BaseX(2)+BaseO(2)],[BaseO(3) BaseX(3)+BaseO(3)], 'Color', 'r','linewidth', 3);
tx = animatedline('MaximumNumPoints',2,'Color', 'r','linewidth', 3);
for i=1:10
    psm_xp1V=psm_xp1V_data.psm_xp1V(:,:,i);
    animation4(tx, psm_xp1V);
end

function animation4(tx, psm_xp1V)
    s=0.1;
    TipO = psm_xp1V(1:3,4);
    TipX = psm_xp1V(1:3,1).*s; 
    addpoints(tx,[TipO(1) TipX(1)+TipO(1)],[TipO(2) TipX(2)+TipO(2)],[TipO(3) TipX(3)+TipO(3)]);
    drawnow;
end