HOW CAN I RE-EDIT MATRIX?
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Hi!
How can "re-edit" this matrix:
[1 3 4;
2 5 7;
3 1 6;
4 2 8]
in this:
[1 4;
1 4;
1 4;
2 7;
2 7;
2 7;
2 7;
2 7;
3 6;
4 8;
4 8]
where each row is replaced for n thimes where n is the second column in the first matrix?
Thank you!
Fabio
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Accepted Answer
José-Luis
on 22 May 2014
your_mat = cell2mat(arrayfun(@(n) repmat(a(n,[1 3]),a(n,2),1),(1:size(a,1))','uniformoutput',false));
More Answers (1)
Geoff Hayes
on 22 May 2014
First determine the dimensions of the new matrix (called B say) which will mx2 where m is the sum of the middle column. Then iterate over each row of your initial matrix (called A say) and replicate the end points of that row (first and third columns) by the value in the second column:
B(j:j+A(i,2)-1,:) = repmat([A(i,1) A(i,3)],A(i,2),1);
where i is the ith row of A and j is the next row to insert your replicated block (with j being incremented on each iteration). So in the above piece of code, we are replacing all rows in B from j to j+A(i,2)-1 with the ends of the ith row of A replicated A(i,2)x1 times.
Hope that the above helps!
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