MATLAB: How to create a matrix from for loop result

for loopmatrix

I repelem the element by the index
D = [170, -80, -30, 0, -50, -30, 20, -60, 100, -60 -20];
Iplus=find(D>0);
for i=1:size(Iplus,2)
    a=ceil(D(Iplus(i))/100);   
    A=repelem(Iplus(i),a*2)
end
How can I store all result as below into one matrix? like A=[1 1 1 1 7 7 9 9]
A =
     1     1     1     1
A =
     7     7
A =
     9     9

Best Answer

D = [170, -80, -30, 0, -50, -30, 20, -60, 100, -60 -20];
Iplus=find(D>0);
A = [] ;           % initialize
for i=1:size(Iplus,2)
    a=ceil(D(Iplus(i))/100);   
    Anew = repelem(Iplus(i),a*2)
    A = [A Anew]   % append
end
Note that Matlab will warn you, because A is growing every iteration. With some thinking you might be able to optimise or even vectorise this piece of code.
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