bugGNU Octave - Bugs: bug #37507, pseudoinverse with sparse matrices

 
 

bug #37507: pseudoinverse with sparse matrices

Submitted by:  Muhali <muhali>
Submitted on:  Thu 04 Oct 2012 09:23:14 PM UTC  
 
Category:  None Severity:  3 - Normal
Priority:  5 - Normal Item Group:  None
Status:  Fixed Assigned to:  None
Originator Name:  Open/Closed:  Closed
Release:  3.6.3 Operating System:  GNU/Linux

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Fri 05 Oct 2012 02:18:42 PM UTC, comment #4: 

It's missing functionality, the ability to compute minimum nomrm sparse solutions. You got a warning message about this at build time, but now you will get an error message at run time too:

    http://hg.savannah.gnu.org/hgweb/octave/rev/9ccf4ffb9fa2

This will be part of the next major release.

Jordi Gutiérrez Hermoso <jordigh>
Project Administrator
Thu 04 Oct 2012 09:50:07 PM UTC, comment #3: 

Because

octave>> sparse(A) \ B
ans = [](0x0)

is an incorrect result rather than a missing functionality a warning/error message to that effect would be helpful.

Muhali <muhali>
Thu 04 Oct 2012 09:43:50 PM UTC, comment #2: 

For future reference, if a warning about missing libraries is indeed what you want, it probably should be inserted here:

http://hg.savannah.gnu.org/hgweb/octave/file/720a3bd76492/liboctave/numeric/sparse-dmsolve.cc#l484

Jordi Gutiérrez Hermoso <jordigh>
Project Administrator
Thu 04 Oct 2012 09:31:50 PM UTC, comment #1: 

Well, if you don't have the required matrix libraries installed, sparse functionality will be lacking. What do you expect instead, a message about missing sparse libraries?

Jordi Gutiérrez Hermoso <jordigh>
Project Administrator
Thu 04 Oct 2012 09:23:14 PM UTC, original submission:  

The following shows that there is a problem with the sparse matrix pseudoinverse.

octave>> A = [2 ; 1]; B = [2 -1 0 ; 3 0 1];
octave>> A \ B
ans =

   1.400  -0.400   0.200

octave>> sparse(A) \ sparse(B)
ans = Compressed Column Sparse (rows = 0, cols = 0, nnz = 0)

octave>> sparse(A) \ B
ans = [](0x0)

I am using 3.6.3 with no extra sparse matrix libraries (AMD,...).

Muhali <muhali>

 

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    Follow 3 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    2012-10-05 jordigh StatusNeed Info => Fixed
        Open/ClosedOpen => Closed
    2012-10-04 jordigh StatusNone => Need Info

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