MATLAB: 1D array values to 2D matrix

1d array2d matrix

I would like to 'convert' a 1D array to a 2D matrix considering the value inside the array as:
A =
     1     3     5     4     3
B =
     1     3     5     4     3
     0     3     5     4     3
     0     3     5     4     3
     0     0     5     4     0
     0     0     5     0     0
Can you suggest a fast way to do that?

Best Answer

A for-loop would make a cleaner read (I could provide that upon request) but here's two lines the do the trick. 
base = cellfun(@(x)repmat(x,x,1), num2cell(A), 'UniformOutput', false);
cell2mat(cellfun(@(y,n) padarray(y,n, 'post'),base, num2cell(max(A)-A), 'UniformOutput', false))
ans =
     1     3     5     4     3
     0     3     5     4     3
     0     3     5     4     3
     0     0     5     4     0
     0     0     5     0     0
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