Info
この質問は閉じられています。 編集または回答するには再度開いてください。
Passing back data with increasing row indices using Sparse Command
1 回表示 (過去 30 日間)
古いコメントを表示
By default the sparse command passes back the non-zero elements in a matrix arranged by increasing column indices:
A = [ 0 0 1; 0 0 2; 0 2 1];
B = sparse(A)
B =
(3,2) 2
(1,3) 1
(2,3) 2
(3,3) 1
Is there a way to change this so that it passes back the sparse matrix in increasing row indices? In this case
B =
(1,3) 1
(2,3) 2
(3,2) 2
(3,3) 1
0 件のコメント
回答 (1 件)
Walter Roberson
2016 年 3 月 17 日
You are confusing the display of B with the content of B. The disp() and display() of sparse matrices is in the order you indicate. However that does not mean that the values are "passed back" in that order, just that they are displayed in that order. (Internally, they are in fact ordered by column, but that is an internal detail.)
You can do this:
[r, c, s] = find(B);
rcs = sort([r,c,s], 2);
fprintf('(%d,%d) %g\n', rcs.'); %the transpose of values is not obvious but it is consistent with the rest of MATLAB
0 件のコメント
参考
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!