[Octave-bug-tracker] [bug #53440] Wrong factorization with ilutp type

[Rik]

Update of bug #53440 (project octave):

                  Status:          Patch Reviewed => Fixed                  
             Open/Closed:                    Open => Closed                 

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Follow-up Comment #4:

@Marco: There is an easier way to compute the transposed, permuted identity
matrix.  Instead of creating the speye matrix, permuting it via indexing, and
then calculationg the transpose of the result, it is possible te just
transpose the permuting index and then use that in a single indexing step.

Here is the code:


-            retval(0) = L + speye.index (perm, idx_vector::colon);
+            retval(0) = L + speye.index (idx_vector::colon, perm);


I benchmarked the original code construction and this method for speye(1e3)
and it was only 18% faster, but that is still worth something.

I checked in the patch here
(http://hg.savannah.gnu.org/hgweb/octave/rev/acb7094aebb3).

Marking as fixed and closing report.


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