MATLAB: How to place NaN at diagonal position in cell array

cell arrays

hey all
a={[],-1,-1,0.8,-0.7,[],[]; [],[],0.9,1,[],-0.9,0.6; -1,[],[],0.9,0.2,[],0.8}
how to place diagonal value in each row of 'a'. Diagonal value can be [] or NaN. Like this
    out={NaN,[],-1,-1,0.8,-0.7,[],[]; [],NaN,[],0.9,1,[],-0.9,0.6; -1,[],NaN,[],0.9,0.2,[],0.8}

Best Answer

a={[],-1,-1,0.8,-0.7,[],[]; [],[],0.9,1,[],-0.9,0.6; -1,[],[],0.9,0.2,[],0.8};
[m,n] = size(a);
z = sort([repmat(1:n,m,1),(1:m)' - .5],2);
t = rem(z.',1) == 0;
out = cell(size(t));
out(t) = a';
out(~t) = {nan};
out = out';
or
a={[],-1,-1,0.8,-0.7,[],[]; [],[],0.9,1,[],-0.9,0.6; -1,[],[],0.9,0.2,[],0.8};
[m,n] = size(a);
out = num2cell(nan(m,n+1));
out(triu(true(m,n+1),1)) = a(triu(true(m,n)));
out(tril(true(m,n+1),-1)) = a(tril(true(m,n),-1));
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