Plotting elements of a matrix in one vertical line for every iteration

The script loops through a set of commands 1000 times. In every iteration, a sparse matrix with some non-zero values are generated.

What I want to do is:

For one iteration, plot all the non-zero elements of the matrix with specific colours(Y-axis) along a vertical line(=iteration number,X-axis). Repeat the same for every iteration. This way I get to see how one particular element of the matrix is varying through every iteration.

This is what I did:

figure();hold on;
for i=1:1000
    %%script to generate Matrix
Matrix;
[row,col,s]=find(Matrix);
for j=1:size(row)
    scatter(i,Matrix(row(j),col(j)));
end
end

Problem: Since I am plotting one element at a time, the colours are random and cannot show how a specific element (say (1,3) of Matrix) varies through the iterations.

[Rik]

You can specify the marker color, so the only thing you'll have to do is come up with a method to convert your index to a specific color.

Answer 1

[Rik]

As I mentioned in my comment, you need to find a way to convert a position in your matrix to a color. In my example below I'm using the linear index to land on the same spot of the colormap.

figure();hold on;
CMap=colormap;
for i=1:1000
    %%script to generate Matrix
    Matrix;
    [row,col,s]=find(Matrix);
    for j=1:size(row)
        c_ind=sub2ind(size(Matrix),row(j),col(j));
        c_ind=mod(c_ind,size(CMap,1))+1;
        c=CMap(c_ind,:);
        scatter(i,Matrix(row(j),col(j)),[],c);
    end
end

You could also edit the code to remove the second loop.

[sharadhi]

I used c(j) instead of c and got what I needed.

Thank you Rik

Answer 2

[KSSV]

YOu can specify a random colour using rand(1,3)