How can I plot a multidimensional array?

Hello, I want to create a gif from the data inside a 32x360x360 double array. The thing is I want to plot the 32 values for each 360x360, I mean plotting first 32x1x1, then 32x1x2, 32x1x3, 32x1x4, ..., 32x1x360, 32x2x1, 32x2x2, and so on making a gif until it reaches 32x360x360. Can this be done?

The next code is one I have if the vector was 32x129600. How can I change it to plot the other vector of one more dimension without reshaping it? As I would like to have a title for the gif with something like i = 1,2,3,4,...360 and j=1,2,3,4,...360 to see how it changes.

for i=1:JN
        plot(Vector(:,i), 'k-', 'LineWidth', 2);
        axis([startpoint finishpoint miny maxy])
        xlabel('Time(s)') 
        ylabel('Relative Brightness')
        grid on

      % Capture the plot as an image 
            frame = getframe(h); 
            im = frame2im(frame); 
            [imind,cm] = rgb2ind(im,256); 
      % Write to the GIF File 
            if i == 1 
                imwrite(imind,cm,filename,'gif', 'Loopcount',inf,'DelayTime',0.1); 
            else 
                imwrite(imind,cm,filename,'gif','WriteMode','append','DelayTime',0.1);
            end 
end

Answer 1

[Walter Roberson]

Make JN = (360*360) .

When you index with fewer indices than there are dimensions, then the last index acts like a linear index relative to that dimension and later. So Vector(:,360) would correspond to Vector(:,360,1) and Vector(:,361) would correspond to Vector(:,2,1)

[Raúl Alonso Merino]

Thank you so much and now if I wanted a title for my plot that changes over time. There are two angles: theta: 0-360º and phi: 0-360º. The array is then 32x360x360 (32xthetaxphi), so how can I put a title that changes first the theta going from 0 to 360 and every time it reaches 360, the phi increases 1 and the theta starts again.

title(['Theta = ' num2str(i)  'º, Phi = ' num2str(i) 'º and Alpha = 0º'])

For example with that one I can only increase both number until they get to 360x360 but I want that theta increases until 360 and then phi increases 1. Like:

Theta = 1º, Phi = 1º ----> Theta = 2º, Phi = 1º ----> Theta = 360º, Phi = 1º ----> Theta = 1º, Phi = 2º and so on.

[Walter Roberson]

theta = floor((i-1)/360);
phi = mod(i - 1, 360);
title( sprintf('Theta = %dº, Phi = %dº and Alpha = 0º', theta, phi));

Note: it is not clear from your question whether theta increases down the columns or across the rows. It is also not clear whether you want 0:1:359 or 1:1:360 .

Also, I notice that you had asked 32x1x1, then 32x1x2, 32x1x3, 32x1x4 but that the technique I provided earlier would go (:,1,1) then (:,2,1) then (:,3,1) and so on. You would want to permute(Vector,[1 3 2]) to access it in the order you are wanting. Or use a double nested loop.

I would suggest to you that a double nested loop would be clearer code. Any efficiency you might gain by using a single loop is negated by having to calculate the theta and phi based upon a single index.

[Raúl Alonso Merino]

Thank you. The data increases along the rows, I mean, each column has 32 points that are the plot of one curve, so I plot each time one curve, which would correspond to a value of theta and phi. Then the next plot would be the 32 points of theta = 2º and phi = 1º, then theta = 3º and phi = 1º and so on. And I want it like 1:1:360.

And sorry I meant 32x1x1, then 32x2x1, 32x3x1 so your technique is the one I needed. The array 32x360x360 is 32xthetaxphi so I need first to run the theta values until 360 so phi increases in one.

And how could I do a double nested loop? Sorry I'm quite stuck with this.

[Walter Roberson]

ax = gca;
first == true;
for theta = 1:360
    for phi = 1:360
        if first
           h = plot(Vector(:,theta, phi), 'k-', 'LineWidth', 2);
           axis(ax, [startpoint finishpoint miny maxy])
           xlabel(ax, 'Time(s)') 
           ylabel(ax, 'Relative Brightness')
           grid(ax, 'on')
        else
            set(h, 'YData', Vector(:,theta,phi))
        end
        title(ax, sprintf('Theta = %dº, Phi = %dº and Alpha = 0º', theta, phi));
        drawnow()
        % Capture the plot as an image 
        frame = getframe(ax); 
        im = frame2im(frame); 
        [imind,cm] = rgb2ind(im,256); 
        % Write to the GIF File 
        if first
          imwrite(imind,cm,filename,'gif', 'Loopcount',inf,'DelayTime',0.1); 
        else 
          imwrite(imind,cm,filename,'gif','WriteMode','append','DelayTime',0.1);
        end
        first = false;
    end
end

[Raúl Alonso Merino]

Thank you so much. The only problem it is changing firstly the phi and after the theta but I suppose it is just changing the two angles at the beginning. But the rest it's perfect.

And the last thing, if I wanted to make a video instead of a gif from the figures how could this be done?

[Walter Roberson]

You can exchange to for phi then for theta without changing the rest.

For creating a video see https://www.mathworks.com/help/matlab/ref/videowriter.html#busy5fx-2

[Raúl Alonso Merino]

Perfect, thank you so much.