MATLAB: How to have the numbers in one vector after a while loop

MATLABmatrixvectorwhile

Let say that I have a matrix A=[1 0 5 4; 2 0 5 4; 3 4 6 2]; and I am using the below code ( see my previews question Plot the numbers of a matrix as points (dots) in a plot) while any(A(:) > 0) [r,c] = find(A>0); X= randn; Y= randn; a=c+X b=r+Y A = A-1; end
it returns for a and b a =
    1.4471
    1.4471
    1.4471
    2.4471
    3.4471
    3.4471
    3.4471
    4.4471
    4.4471
    4.4471
b =
    1.5364
    2.5364
    3.5364
    3.5364
    1.5364
    2.5364
    3.5364
    1.5364
    2.5364
    3.5364
a =
    0.6514
    0.6514
    1.6514
    2.6514
    2.6514
    2.6514
    3.6514
    3.6514
    3.6514
b =
    3.1841
    4.1841
    4.1841
    2.1841
    3.1841
    4.1841
    2.1841
    3.1841
    4.1841
a =
    1.2058
    2.2058
    3.2058
    3.2058
    3.2058
    4.2058
    4.2058
b =
    3.1324
    3.1324
    1.1324
    2.1324
    3.1324
    1.1324
    2.1324
a =
    1.4771
    2.4771
    2.4771
    2.4771
    3.4771
    3.4771
b =
    3.9398
    1.9398
    2.9398
    3.9398
    1.9398
    2.9398
a =
    1.6379
    1.6379
    1.6379
b =
    0.2081
    1.2081
    2.2081
a =
    3.6630
b =
    3.5855
how can I have all the numbers of a and b in one vector respectively ?

Best Answer

Although it is slightly different in operation, you could try this:
A = [1 0 5 4; 2 0 5 4; 3 4 6 2];
N = sum(A(:));
X = randn(N,1)/12;
Y = randn(N,1)/12;
[R,C] = find(A>0);
B = A(A>0);
X = X + cell2mat(arrayfun(@(z,m)repmat(z,m,1),C,B,'UniformOutput',false));
Y = Y + cell2mat(arrayfun(@(z,m)repmat(z,m,1),R,B,'UniformOutput',false));
scatter(X,Y,[],randperm(N),'filled')
axis(gca,'ij')
colormap('winter')
which generates this figure:
The main differences from your code is that it generates all values at once (in the vectors X and Y) rather than within a loop, and it also uses a different random position for each point (rather than applying one random value to all points at each step of the while-loop). The code assumes that all values of A are positive integers or zero.
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