[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Octave-bug-tracker] [bug #45080] normest does not work with sparse comp
From: |
Rik |
Subject: |
[Octave-bug-tracker] [bug #45080] normest does not work with sparse complex matrices |
Date: |
Tue, 12 May 2015 15:14:09 +0000 |
User-agent: |
Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:37.0) Gecko/20100101 Firefox/37.0 |
Update of bug #45080 (project octave):
Status: None => Fixed
Open/Closed: Open => Closed
Release: 3.8.2 => 4.0.0-rc4
_______________________________________________________
Follow-up Comment #1:
I think the idea behind using trace() was to have some value that was
correlated with the matrix and that was quick to calculate. The problem I see
with using just a single value of the matrix (A(1,1)) is that this is likely
to be the same value for millions of sparse matrices (it will be 0 since the
matrix is sparse and only a few entries are non-zero).
I did a benchmark with
s = sprand (1e5, 1e5, 1e-7)
tic; y = trace (s); toc
Elapsed time is 0.00295806 seconds.
The time, 3 milliseconds, just isn't that significant.
I think the best choice is to convert the single trace value to full. I made
that change here (http://hg.savannah.gnu.org/hgweb/octave/rev/cc5ffacb15ab).
_______________________________________________________
Reply to this item at:
<http://savannah.gnu.org/bugs/?45080>
_______________________________________________
Message sent via/by Savannah
http://savannah.gnu.org/