# Insert "1" at specific ranges in a matrix

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monkey_matlab on 27 Nov 2016
Edited: Andrei Bobrov on 28 Nov 2016
Hello,
I am trying to generate a 40 x 360 matrix that has 1's every 9 columns. After the 9th column, the 1's should now be in the second row and from columns 10-18. After the 18th column, the 1's will now be in the 3rd row and from columns 19-27 and so on...
The matrix will look like this:
1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 ...
0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 0 0 ...
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 ...
...
Is there an easy way to generate this matrix?
This is what I have so far :-(
aa = zeros(40,360);
bb = ones(1,9);

Image Analyst on 27 Nov 2016
Here's a way that you may consider "simple":
aa = zeros(40,360);
for row = 1 : size(aa, 1)
col = 9*(row-1)+1;
aa(row, col:col+8) = 1;
end

Andrei Bobrov on 28 Nov 2016
Edited: Andrei Bobrov on 28 Nov 2016
z =repmat({ones(1,9)},40,1);
out = blkdiag(z{:});
or
out = kron(eye(40),ones(1,9));

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