CoCoA » CoCoALib

28 May 2019

14:45 Feature #1283 (In Progress): Printing for (prime) finite fields

I am aware that in CoCoALib one can create two rings which are essentially "identical", but are not considered as bei... John Abbott

11 May 2019

21:57 Feature #1283: Printing for (prime) finite fields

Consider the following session:... John Abbott

21:53 Feature #1283 (Closed): Printing for (prime) finite fields

I have found a "useful" result in an old file.
Unfortunately the result contains printed forms of the RingHoms used ... John Abbott

05 May 2019

10:07 Feature #1282 (New): subresultant

A long time ago Ring Xiao sent an implementation of Ducos's subresultant chain algorithm.
Clean it, and incorporate ... John Abbott

04 May 2019

21:05 Bug #1281: Factor of multivariate sometimes prints ERROR

The simplest examples (with 3 terms) seem to be of deg 7 (none found in deg 6 or deg 5).... John Abbott

20:55 Bug #1281 (New): Factor of multivariate sometimes prints ERROR

Here is an example:... John Abbott

03 May 2019

20:36 Bug #1280: Determinant & Inverse of matrix over non integral domain

I'm now wondering what is the difference between @ConstMatrixViewBase::myDet@ and @DenseMatImpl::myDet@... John Abbott

16:35 Bug #1280: Determinant & Inverse of matrix over non integral domain

I'd like to rewrite @ConstMatrixViewBase::myDet@ so that it calls the "fast" impls for small matrices. How to do thi... John Abbott

15:59 Bug #1280 (In Progress): Determinant & Inverse of matrix over non integral domain

Some thoughts about computing the determinant.
There is special case code for:
* small matrices (up to 5x5 incl.)... John Abbott

13:57 Bug #1280: Determinant & Inverse of matrix over non integral domain

Here is a simple failing case:... John Abbott

13:51 Bug #1280 (In Progress): Determinant & Inverse of matrix over non integral domain

CoCoA gives unnecessary errors when computing det or inverse of a matrix over a non-integral domain.
Rectify! John Abbott

14:05 Support #1263: Tidy CoCoALib test directory

I have just checked that running *all* @test-bugNNN@ executables takes about 0.03s on my computer. Since these files... John Abbott

13:45 Feature #303: Rows and Columns of a matrix

I have now added @GetRow@, @GetCol@, @GetRows@ and @GetCols@ to @MatrixOps.txt@
Fixed a couple of minor bugs. Is ... John Abbott

13:24 Feature #303 (Resolved): Rows and Columns of a matrix

I have just implemented @GetRow@, @GetCol@, @GetRows@ and @GetCols@.
Perhaps the names are not ideal, but they are... John Abbott

11:47 Design #1279 (Closed): Tidy up code for matrix determinant

I recently encountered an unexpected error while trying to compute the determinant of a 2x2 matrix over @ZZ/(841)@ wh... John Abbott

11:42 Feature #1278 (New): Port old "clever" code for matrix determinant over ZZ to CoCoALib

In CoCoA-4 there was a "clever" implementation of matrix determinant(over ZZ) based on the paper with Bronstein and M... John Abbott

11:39 Feature #11 (Closed): Bareiss algorithm

This was done ages ago. It has been working trouble-free for over 2 years.
Closing. John Abbott

11:35 Slug #691 (Closed): Matrix determinant over ZZ

I think this was resolved some time ago when I arranged for the code to recognise the case that the entries are all i... John Abbott

30 Apr 2019

17:18 Design #925: MachineInt or long for args which are indices (yet again)

Postponing because there are too many other more pressing issues. Anyway the current code works adequately, so it is... John Abbott

11:51 Feature #813: Implement "elim" in CoCoALib

It would be nice to complete this before the next release! To this end, I have increased the priority... John Abbott

10:54 Feature #1277: Gaussian row reduction

NTL's doc shows just one fn *@gauss@* which accepts 2 args: matrix @M@ and an optional integer @w@ (default is number... John Abbott

10:44 Feature #1277: Gaussian row reduction

The request seems reasonable to me.
Not yet sure what the best design might be, but I suggest the following as a s... John Abbott

10:40 Feature #1277 (Closed): Gaussian row reduction

Julian Danner (Passau) would like CoCoA to offer matrix row reduction via gaussian elimination.
Discuss, design, i... John Abbott