CoCoA Project

30 May 2019

12:10 CoCoA-5 Design #1292 (New): Interpreter: fns which accept INT or RAT

There are quite a few functions which accept as arg @INT@ or @RAT@.
The current solution is to call @evalArgAsT1or... John Abbott

29 May 2019

11:28 CoCoA-5 Feature #1289: assert-function for cocoa5

May I ask why you want to have assertions which can be globally enabled/disabled?
[I know that this is what we do in... John Abbott

28 May 2019

14:45 CoCoALib 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

10:38 CoCoA-5 Feature #1289: assert-function for cocoa5

Here is a potential impl:... John Abbott

10:32 CoCoA-5 Feature #1289: assert-function for cocoa5

Would someone like to post a couple of hypothetical examples of how you might like to use this feature (so that we ca... John Abbott

27 May 2019

21:17 CoCoA-5 Bug #1291 (New): LinearSimplify: somtimes not optimal

Sometimes @LinearSimplify@ could produce a simpler result:... John Abbott

14:35 CoCoA-5 Feature #1290 (Resolved): NewPolyRing: allow symbols with just head and no indices?

I have modified the fn @evalArgAsListOfSymbols@ so that it accepts records with just a @head@ field and no @indices@ ... John Abbott

13:26 CoCoA-5 Feature #1290: NewPolyRing: allow symbols with just head and no indices?

The manual page for @NewPolyRing@ could be improved (and made shorter).
I find the discussion about @::=@ to be an u... John Abbott

13:21 CoCoA-5 Feature #1290 (Closed): NewPolyRing: allow symbols with just head and no indices?

It seems superfluous to have to specify an empty list of indices if one wants no indices; should we allow the @indice... John Abbott

24 May 2019

17:43 CoCoA-5 Bug #1288: len for RINGELEM ?!?

The source code for the function @len@ is in file @BuiltinFunctions-CoCoALib.C@ around line 100.
The code recognis... John Abbott

16:25 CoCoA-5 Bug #1288: len for RINGELEM ?!?

The manual entry for @len@ looks a bit strange, and is hard to read. It says the fn signature is... John Abbott

16:22 CoCoA-5 Bug #1288 (Closed): len for RINGELEM ?!?

I was surprised to discover that @len@ can be applied to a @RINGELEM@.... John Abbott

23 May 2019

15:13 CoCoA-5 Support #1287 (In Progress): Better err mesg for easy typo in ring definition

The relevant source code is in @Parser.C@ around line 360 in the function @parseUseStatement@.
I think it may be ... John Abbott

12:16 CoCoA-5 Support #1287 (Closed): Better err mesg for easy typo in ring definition

Consider this excerpt:... John Abbott

11:53 CoCoA-5 Feature #1285: New Fn: make a homogeneous list of ringelem

What exactly should the function do? What should it be called?
* *(A)* simplest is to accept @RINGELEM@ and @INT@... John Abbott

11:30 CoCoA-5 Feature #1285 (New): New Fn: make a homogeneous list of ringelem

Proposal: create a new function which takes a ring and a list, and returns a list of RINGELEM belonging to the speci... John Abbott

11:48 CoCoA-5 Bug #1286: Website: trouble with the world map

I'm very unhappy about the CPU "burning" (it might well be a Google revenge tactic).
Also after visiting the page ... John Abbott

11:46 CoCoA-5 Bug #1286 (Closed): Website: trouble with the world map

The world map showing where visitors to the CoCoA website come from causes trouble in "private mode" in Firefox:
* t... John Abbott

11:23 CoCoA-5 Design #1120: Web site

Should we close this? Ater all 5.2.4 has been released.
What about the problem with "forever loading"?
John Abbott

11:17 CoCoA-5 Feature #1272: Groebner Bases over ZZ

Florian Walsh (Passau) has an prototype implementation of GBasis over ZZ, currently as a package in CoCoA-5. He is w... John Abbott

22 May 2019

22:05 CoCoA-5 Slug #1284 (Resolved): CartesianProductList: too slow

I suspect that the main problem is that @append@ is terribly slow -- I'm pretty sure it makes needless copies.
Her... John Abbott

16:30 CoCoA-5 Slug #1284: CartesianProductList: too slow

@CartesianProductList@ is defined in @list.cpkg5@
Ange reported that @CartesianProductList@ is slow; maybe I had a... John Abbott

16:18 CoCoA-5 Slug #1284: CartesianProductList: too slow

The examples above are not tiny, but also not so large. The resulting lists contained 32768 elements, and each eleme... John Abbott

16:15 CoCoA-5 Slug #1284 (Closed): CartesianProductList: too slow

Cartesian product operator is much faster than @CartesianProductList@.
Example:... John Abbott

11 May 2019

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

Consider the following session:... John Abbott

21:53 CoCoALib 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

20:47 CoCoA-5 Support #1006: External dependencies for building

I have just tried building CoCoA-5 on my old MacBook, and it failed because java is not installed.
* it is annoyin... John Abbott

05 May 2019

10:07 CoCoALib 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 CoCoALib 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 CoCoALib Bug #1281 (New): Factor of multivariate sometimes prints ERROR

Here is an example:... John Abbott

03 May 2019

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

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

13:51 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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