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What wrong with the indexing code?

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GEORGIOS BEKAS
GEORGIOS BEKAS 2018-2-8
评论： GEORGIOS BEKAS 2018-2-8
If I want to fill in a matrix, of which I have its indices without a for loop, how could I do it? Suppose that the (row(i),col(i)) elements to be filled are given.
value = 189;
row = [ 1 3 6 7 8 ];
col = [ 1 1 4 4 5];
B(row,col) = value

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采纳的回答

Walter Roberson
Walter Roberson 2018-2-8
B = full( sparse(row, col, value) );
or
B = accumarray([row(:), col(:)], value);
  2 个评论
GEORGIOS BEKAS
GEORGIOS BEKAS 2018-2-8
how about using arrayfun/bsxfun or something?
Walter Roberson
Walter Roberson 2018-2-8
Not at all easily with arrayfun or bsxfun as assignment through function calls is difficult and never less than ugly.

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更多回答（1 个）

Birdman
Birdman 2018-2-8
B(sub2ind([max(row) max(col)],row,col)) = value
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Birdman
Birdman 2018-2-8
Doesn't my answer also work Walter?

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