2D plot and animation

figure();
plot(x(:,1),x(:,3),'b',x(:,5),x(:,7),'r',x(:,9),x(:,11),'g')
axis([0 15 0 15])

I want to make a animation to plot the graph as shown. i.e it should start with initial point and slowly goes giving me an animation. The normal graph is coming but I want it in the form of animation. Can someone please help me in this?

Answer 1

[Walter Roberson]

I recommend using animatedLine()

But you could also consider comet()

[Walter Roberson]

L1 = animatedline('color', 'b');
L2 = animatedline('color', 'r');
L3 = animatedline('color', 'g');

for K = 1 : size(x,1)
   addpoints(L1, x(K,1), x(K,3) );
   addpoints(L2, x(K,5), x(K,7) );
   addpoints(L3, x(K,9), x(K,11) );
   drawnow update;
end

[Abhibrata Adhikary]

Thank you so much Walter. It worked.

[Nikolaos Zafirakis]

What can you do if x is a time unit?

x = 
'23-Jun-2017 08:34:18'
'23-Jun-2017 08:34:29'
'23-Jun-2017 08:34:39'

[Walter Roberson]

For the last few years you have been able to convert time units to datetime() objects and plot them directly, such as

xdt = datetime(x);
plot(xdt, y)

[Nikolaos Zafirakis]

Yes my data is already in that format what if:

L1 = animatedline('color', 'b');
L2 = animatedline('color', 'r');
L3 = animatedline('color', 'g');

xdt = datetime(x);
for K = 1 : size(x,1)
   addpoints(L1, xdt(K,1), x(K,1) );
   addpoints(L2, xdt(K,1), x(K,2) );
   addpoints(L3, xdt(K,1), x(K,3) );
   drawnow update;
end


% Error using matlab.graphics.animation.AnimatedLine/addpoints
% Invalid type for argument X. Type must be double.

[Walter Roberson]

I see what you mean, animatedLine is restricted to double.

But you also have the problem that x is still a cell array of character vectors, so plotting x(K,1) as the y coordinate is not possible.

Below, I will assume that you have a numeric matrix Y(K,1:3) [though it could also be datetime or duration or categorical instead of numeric.]

In that case you need older techniques:

L1 = plot(nan, nan, 'b');
L2 = plot(nan, nan, 'r');
L3 = plot(nan, nan, 'g');
xdt = datetime(x);
for K = 1 : size(xdt,1)
    cxdt = xdt(1:K);
    set(L1, 'XData', cxdt, 'YData', Y(1:K,1));
    set(L2, 'XData', cxdt, 'YData', Y(1:K,2));
    set(L3, 'XData', cxdt, 'YData', Y(1:K,3));
    drawnow limit;
end

[Nikolaos Zafirakis]

So I tried it and i got this error. Is there a was around this?

Error using matlab.graphics.chart.primitive.Line/set
Invalid or deleted object.

Error in Untitled (line 35)
    set(L1, 'XData', cxdt, 'YData', Y(1:K,1));

[Walter Roberson]

L1 = plot(nan, nan, 'b');
hold on
L2 = plot(nan, nan, 'r');
L3 = plot(nan, nan, 'g');
hold off
xdt = datetime(x);
for K = 1 : size(xdt,1)
    cxdt = xdt(1:K);
    set(L1, 'XData', cxdt, 'YData', Y(1:K,1));
    set(L2, 'XData', cxdt, 'YData', Y(1:K,2));
    set(L3, 'XData', cxdt, 'YData', Y(1:K,3));
    drawnow limit;
end

[Nikolaos Zafirakis]

Well the datetime does not work, it errors so I changed the time unit to Julian date, and it works. However, I would prefer it to work with the UTC data and time. If you have any further suggestions, please let me know. Thank you for your help!!

Error using matlab.graphics.chart.primitive.Line/set
Value must be a vector of numeric type

Error in Untitled (line 35)
set(L1, 'XData', cxdt, 'YData', Y(1:K,1));

[Walter Roberson]

L1 = plot(NaT, nan, 'b');
hold on
L2 = plot(NaT, nan, 'r');
L3 = plot(NaT, nan, 'g');
hold off
xdt = datetime(x);
for K = 1 : size(xdt,1)
    cxdt = xdt(1:K);
    set(L1, 'XData', cxdt, 'YData', Y(1:K,1));
    set(L2, 'XData', cxdt, 'YData', Y(1:K,2));
    set(L3, 'XData', cxdt, 'YData', Y(1:K,3));
    drawnow limit;
end

[Nikolaos Zafirakis]

Thank you, for you help. If you could check this out to it would be helpful!

https://uk.mathworks.com/matlabcentral/answers/481402-how-to-create-subplots-in-an-animation

[Noah Prisament]

The "animatedline" now supports "datetime" values natively, so this functionality can now be acheived using "animatedline" and "addpoints" if the AnimatedLines are initialized as follows:

L1 = animatedline(NaT, NaN, 'color', 'b');
L2 = animatedline(NaT, NaN, 'color', 'r');
L3 = animatedline(NaT, NaN, 'color', 'g');

[Walter Roberson]

Thanks, @Noah Prisament

Answer 2

[Abhibrata Adhikary]

Can you give an example to show the working?

Answer 3

[Hussein]

clc clear all close all Z = peaks; surf(Z) axis tight set(gca,'nextplot','replacechildren','visible','off') f = getframe; [im,map] = rgb2ind(f.cdata,256,'nodither'); im(1,1,1,20) = 0; for k = 1:20 surf(cos(2*pi*k/20)*Z,Z) f = getframe; im(:,:,1,k) = rgb2ind(f.cdata,map,'nodither'); end imwrite(im,map,'DancingPeaks.gif','DelayTime',0.1,'LoopCount',inf) %g443800