Mercurial > octave-nkf
changeset 19979:941e782d0429
gallery: performance increase for minij matrix.
* special-matrix/gallery.m: make use of broadcasting @min for performance
increase. The increase is dependent on the value N, as it avoids the
construction of 2 NxN matrices.
| author | Carnë Draug <carandraug@octave.org> |
|---|---|
| date | Sat, 14 Mar 2015 14:52:58 +0000 |
| parents | 88233ac3f3ea |
| children | f7a805f02723 |
| files | scripts/special-matrix/gallery.m |
| diffstat | 1 files changed, 5 insertions(+), 1 deletions(-) [+] |
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--- a/scripts/special-matrix/gallery.m Sat Mar 14 15:20:51 2015 +0100 +++ b/scripts/special-matrix/gallery.m Sat Mar 14 14:52:58 2015 +0000 @@ -1784,7 +1784,7 @@ error ("gallery: N must be an integer for minij matrix."); endif - A = min (ones (n, 1) * (1:n), (1:n)' * ones (1, n)); + A = bsxfun (@min, 1:n, (1:n)'); endfunction function A = moler (n, alpha = -1) @@ -2867,3 +2867,7 @@ %!error <matrix binomial not implemented> gallery ("binomial") %!error <unknown matrix with NAME foobar> gallery ("foobar") +%!assert (gallery ("minij", 4), [1 1 1 1; 1 2 2 2; 1 2 3 3; 1 2 3 4]) +%!assert (gallery ("minij", 1), 1) +%!assert (gallery ("minij", 0), []) +%!assert (gallery ("minij", -1), [])