CoCoA » CoCoALib

11 Jun 2015

20:06 Feature #728: Noncommutative algebra "of solvable type"

As I am sitting in a delayed train with too much time at hand, some further comments:
1.) The "book" by Levandovsk... Werner M Seiler

15:27 Feature #728: Noncommutative algebra "of solvable type"

Going to a seminar here about G-bases in PBW algebras :-)
*NOTE* the seminar was OK. The student pointed out that (... John Abbott

11:43 Feature #728 (In Progress): Noncommutative algebra "of solvable type"

Yes, we should get the old @RingWeyl@ code working again -- my guess is that there is little to do.
We should find... John Abbott

11:30 Feature #728: Noncommutative algebra "of solvable type"

We have already done most of these considerations for RingWeyl (except for the coefficient rule).
.. and we also had... Anna Maria Bigatti

11:14 Feature #728: Noncommutative algebra "of solvable type"

Werner pointed out that a simplistic implementation is likely to be terribly slow (though perhaps "obviously correct"... John Abbott

19:00 Feature #735 (Resolved): Convert a PPMonoidElem to RingElem with coefficient one

done, checked in.
So far I modified only the files in AlgebraicCore Anna Maria Bigatti

11:46 Feature #735: Convert a PPMonoidElem to RingElem with coefficient one

OK, do it! Including @monomial(P,expv)@.
Don't forget documentation, examples and tests!
John Abbott

11:24 Feature #735: Convert a PPMonoidElem to RingElem with coefficient one

My preference (by far) goes to @monomial(P, pp)@
I have already implemented and all tests pass.
Should I also do @m... Anna Maria Bigatti

11:04 Feature #735: Convert a PPMonoidElem to RingElem with coefficient one

I point out that assignment to @RingElem@ can perform some type changes. Should we allow assignment to a @RingElem@ ... John Abbott

11:00 Feature #735: Convert a PPMonoidElem to RingElem with coefficient one

I do agree that, without familiarity with the function, upon reading @monomial(P,1,pp)@ my first thought would be "Wh... John Abbott

10:46 Feature #735: Convert a PPMonoidElem to RingElem with coefficient one

I didn't know that @monomial(P, 1, pp)@ works as expected.
But I think for the _normal_ user who wants to use a @PP... Mario Albert

10:41 Feature #735: Convert a PPMonoidElem to RingElem with coefficient one

I am a little uncertain about the proposal. @monomial(P,pp)@ gains little over @monomial(P,1,pp)@.
Is it worth cr... John Abbott

08:56 Feature #735: Convert a PPMonoidElem to RingElem with coefficient one

Should we do the same for @monomial(P, expv)@?
I cannot see any ambiguity.
*REPLY* (JAA) if we have @monomial(P,PP)@... Anna Maria Bigatti

08:41 Feature #735 (In Progress): Convert a PPMonoidElem to RingElem with coefficient one

That seems very reasonable: I had a look at the code and, indeed, most of the times @monomial@ is called the coeffici... Anna Maria Bigatti

08:31 Feature #735 (Closed): Convert a PPMonoidElem to RingElem with coefficient one

Let @pp@ be a @PPMonoidElem@ of the @PPMonoid@ @PPM@. Let @P@ be a @SparsePolyRing@ with @PPM@ as @PPMonoid@.
Severa... Mario Albert

15:26 Feature #664 (In Progress): Impl small non-prime finite fields (using logs)

JAA has implemented a first prototype (following the model @RingFpImpl@ and @SmallFpImpl@). The computational part u... John Abbott

14:58 Feature #386: add resolution data type

Hans says that singular uses more or less the design we are considering; apparently in some cases they store two reso... John Abbott

11:57 Feature #386: add resolution data type

One possibility might be to have a "module view" much like @MatrixView@, but I'm far from certain whether such a thin... John Abbott

11:43 Feature #386: add resolution data type

> Since the C++ types of the input are different it seems simplest to have different classes for each case. Each cla... Anna Maria Bigatti

08:24 Feature #665: Integrate Janet/Pommaret basis code

In the following I try to explain how I integrated the JBMill/PBMill into @SparsePolyRing::IdealImpl@:
h3. UIBC
... Mario Albert

10 Jun 2015

17:12 Feature #728: Noncommutative algebra "of solvable type"

For starters Ore algebra as a simple case of polynomial algebras of solvable type should be enough. Their main advant... Werner M Seiler

12:55 Feature #728: Noncommutative algebra "of solvable type"

I made a slight mistake in the original description. It should have been:
* @x[i]*x[j] = q*x[j]*x[i] + tail@ where @... John Abbott

14:24 Slug #725: Example database: Slow ideal equality test

John Abbott wrote:
> In the specific example of this issue there are 36 indets (all used), 15 polynomials, and @dim(... Anna Maria Bigatti

13:41 Feature #386 (In Progress): add resolution data type

Mario and I have discussed some possible designs; neither of us has much experience with resolutions, so it is possib... John Abbott

13:19 Feature #729 (In Progress): Betti numbers, betti diagram

Mario suggested that the internal representation should be @vector< map<degree, long> >@.
The resolution is a list... John Abbott

11:30 Feature #730: Stats in GBMill (GReductor)

I suppose Mario ought to write about this. He has followed my design suggestion, and seems to be happy with it. If ... John Abbott

11:24 Feature #730: Stats in GBMill (GReductor)

Mario asked about gathering stats for his involutive basis code.
I suggested using a @struct@ to keep all the stats ... John Abbott

11:18 Feature #730 (Closed): Stats in GBMill (GReductor)

There is already some implementation for gathering stats in G-basis computation.
Review it!
Perhaps separate st... John Abbott

08 Jun 2015

22:27 Feature #728: Noncommutative algebra "of solvable type"

Sounds like a generalisation of RingWeyl.
... Werner, are you willing to test it out? ;-)
I was thinking of porti... Anna Maria Bigatti

18:45 Feature #728 (In Progress): Noncommutative algebra "of solvable type"

Werner asked about the possibility of having non-commutative algebras of solvable type. They are nice enough that Bu... John Abbott

18:52 Feature #729: Betti numbers, betti diagram

Mario points out that for a non-graded case we will also need a datastructure.
*UPDATE* (20150608) Mario thinks it is... John Abbott

18:50 Feature #729 (In Progress): Betti numbers, betti diagram

Design a good data structure for storing Betti numbers (also for multigraded case).
John Abbott

11:09 Feature #718: Insert calls to CheckForInterrupt

Mario asked about the possible run-time cost of calling @CheckForInterrupt@.
Currently it may be needlessly expensiv... John Abbott

07 Jun 2015

12:46 Slug #725: Example database: Slow ideal equality test

In the specific example of this issue there are 36 indets (all used), 15 polynomials, and @dim(P/I)@ gives 21. Isn't... John Abbott

06 Jun 2015

22:49 Slug #725: Example database: Slow ideal equality test

For completeness here is the list of generators in @QQ[x[1..6,1..6]]@ ... John Abbott

22:46 Slug #725: Example database: Slow ideal equality test

Anna, you are right (in principle). In practice, I think almost the whole time is spent computing a G-basis (rather ... John Abbott

21:17 Slug #725: Example database: Slow ideal equality test

Instead of checking equality you should just check whether g_j is in the ideal generated by the others. However, thi... Anna Maria Bigatti

20:32 Slug #725: Example database: Slow ideal equality test

It has finally finished:... John Abbott

14:25 Slug #725: Example database: Slow ideal equality test

Progress...... John Abbott

13:19 Slug #725: Example database: Slow ideal equality test

Re-running the program (over @QQ@) I get the following output (still incomplete):... John Abbott

13:14 Slug #725 (New): Example database: Slow ideal equality test

This is probably not important, but I wanted to record this example which seems to be unexpectedly slow -- it might b... John Abbott

01 Jun 2015

22:31 Slug #722 (In Progress): valuation slow for large inputs

I have implemented a version which divides repreatedly by the largest power of the prime which fits into @unsigned lo... John Abbott

10:39 Slug #722: valuation slow for large inputs

Probably @QuoRem@ is a more sensible choice than @gcd@.
John Abbott

31 May 2015

11:58 Slug #722: valuation slow for large inputs

Source code is in @NumTheory.C@.
It is just a very simple loop. Presumably I could test divisibility by a small pow... John Abbott

11:56 Slug #722 (Closed): valuation slow for large inputs

I tried @valuation(5,factorial(1000000))@ and it took too long.
Make @valuation@ faster if the prime is small (and... John Abbott

30 May 2015

14:52 Feature #721: CheckForInterrupt: string arg to specify where it was called?

I have implemented my suggestion in note 1.
It occurred to me that if we do allow a string as arg (to where @Check... John Abbott

10:01 Feature #721 (In Progress): CheckForInterrupt: string arg to specify where it was called?

I prefer that the exception thrown is not of the same type as a normal @CoCoA_ERROR@ because the reasons behind the e... John Abbott

10:22 Feature #385: Design new errors using inheritance

I think it may be a cleaner design to use (impose) the convention that all exceptions CoCoALib are derived from a sin... John Abbott

29 May 2015

17:20 Feature #721: CheckForInterrupt: string arg to specify where it was called?

In fact I was suggesting something else: @CheckInterrupt@ throws something which is not a CoCoA_ERROR, so cocoa-5 doe... Anna Maria Bigatti

16:19 Feature #721: CheckForInterrupt: string arg to specify where it was called?

It looks to be almost trivial to add @CheckForInterrupt(const char*)@ and @CheckForInterrupt(const std::string&)@.
... John Abbott

16:16 Feature #721 (Closed): CheckForInterrupt: string arg to specify where it was called?

Anna indirectly suggested that it might be nice to have an optional arg to @CheckForInterrupt@ which takes a string i... John Abbott

12:03 Feature #718 (In Progress): Insert calls to CheckForInterrupt

Nice! I added it into @TmpGReductor.C@ (I was actually doing something else with very slow GB ;-) )... Anna Maria Bigatti

22 May 2015

13:45 Slug #675: Matrix determinant over multivariate poly ring

A Google search for "division free algorithm for determinant" produces several hits. Possibly something there may be... John Abbott

13:21 Slug #675 (In Progress): Matrix determinant over multivariate poly ring

I have changed @myDet@ in @DenseMatrix.C@ so that it calls @DetDirect@ only if there are at least 3 indets and the ma... John Abbott

21 May 2015

16:02 Bug #666 (Feedback): RatReconstructByLattice fails in some simple cases

I have added a comment to the documentation.
I discussed with Christof the possibility of throwing an exception wh... John Abbott

10:54 Feature #718: Insert calls to CheckForInterrupt

I suggest we keep a log here of the files we have looked at with a view to inserting calls to @CheckForInterrupt@. John Abbott

10:52 Feature #718 (Closed): Insert calls to CheckForInterrupt

So that interrupts are acted upon we must insert calls to @CheckForInterrupt@ in various places -- principally in loo... John Abbott

09:41 Feature #714 (Resolved): Interrupt mechanism

I have checked in the impl with both *(A)* and *(B)*.
Then I deleted *(A)* and checked in again. This way I hope *(... John Abbott

09:38 Feature #715 (Resolved): RandomSubsetIndices, RandomTupleIndices?

I have already reported this (and logged time) in issue #622.
I think @RandomSubsetIndices@ is likely to be useful... John Abbott

20 May 2015

19:13 Feature #573: Use symbolic links for external libraries

John Abbott wrote:
> What is the current status? Has the cleaning been done? It has been working fine for several ... Anna Maria Bigatti

17:24 Feature #573 (Feedback): Use symbolic links for external libraries

What is the current status? Has the cleaning been done? It has been working fine for several months, so changing st... John Abbott

12:47 Feature #715 (Closed): RandomSubsetIndices, RandomTupleIndices?

In CoCoA we have *RandomSubsetIndices, RandomTupleIndices*.
Could they be useful in CoCoALib?
If so implement trans... Anna Maria Bigatti

12:38 Feature #714: Interrupt mechanism

John Abbott wrote:
> Is there any sense in offering approach *(A)*? Perhaps it is best to offer just *(B)*, and add ... Anna Maria Bigatti

12:21 Feature #714: Interrupt mechanism

I am undecided about which ways to offer for telling the GlobalManager which interrupt flag to watch:
* *(A)* specif... John Abbott

10:22 Slug #675: Matrix determinant over multivariate poly ring

in the cocoa manual there is this example... Anna Maria Bigatti

19 May 2015

17:55 Feature #714: Interrupt mechanism

Also seems to work with the C5 GUI now :-)
John Abbott

16:56 Feature #714 (In Progress): Interrupt mechanism

I have implemented a first version following the outlines given above.
It seems to pass a quick test -- I have mad... John Abbott

11:41 Feature #714: Interrupt mechanism

Here is a further complication: how to handle several libraries together?
Let us suppose that CoCoALib has a mechani... John Abbott

10:16 Feature #714: Interrupt mechanism

There is a slight risk in my proposal above. If @SignalInterrupt@ is called asynchronously while @CheckForInterrupt@... John Abbott

10:09 Feature #714: Interrupt mechanism

As far as CoCoA-5 is concerned CoCoALib is "external software", and the problem noted in #713 applies as much to CoCo... John Abbott

10:04 Feature #714 (Closed): Interrupt mechanism

Add an interrupt mechanism to CoCoALib.
John Abbott

18 May 2015

12:16 Feature #222: Printing polynomials - spaces between terms

This issue has been idle for another year.
John Abbott

17 May 2015

10:31 Design #710: Update normaliz interface?

The revised @normaliz@ interface aims to be backward compatible.
JAA prefers the new names in @normaliz@, and woul... John Abbott

10:29 Design #710 (In Progress): Update normaliz interface?

Normaliz is about to release version 3.0.
This has a revised interface (_e.g._ new names for certain existing feat... John Abbott

10:27 Feature #253: W.Bruns's wish list

Can we finish this issue in the near future?
John Abbott

15 May 2015

19:28 Design #683 (Resolved): Module index component in internal compressed representation

tested both with @unsigned int@ and @unsigned char@: it works!!... Anna Maria Bigatti

18:43 Design #683: Module index component in internal compressed representation

Bug probably found.... my fault
John has implemented in GBEnv.C... Anna Maria Bigatti

19:11 Design #707 (In Progress): MatrixOrderingMod32749Impl: test and write documentation!

Some notes:
In @OrdvArith.H@ there is this comment:... Anna Maria Bigatti

18:47 Design #707 (In Progress): MatrixOrderingMod32749Impl: test and write documentation!

32749 is the biggest prime with some guarantee for <I-cant-remember-what>, so the order matrix is actually over ZZ/(3... Anna Maria Bigatti

15:51 Bug #705 (Feedback): DetDirect calls myAddMul with 0 argument -- funny compilation problem??

I still don't understand why it seemed to work (maybe a missing cvs checkout)
The problem is a simple (when you know ... Anna Maria Bigatti

12:28 Bug #705 (Closed): DetDirect calls myAddMul with 0 argument -- funny compilation problem??

with (CoCoA-5) input:... Anna Maria Bigatti

09:12 Design #703 (New): Add more operations between modules (CoCoALib)

Add more module operations: +, colon, ...
(there are also some operations for modules in CoCoA-5 packages)
The ma... Anna Maria Bigatti

13 May 2015

17:59 Feature #658: Indets actually in a poly (or vector or matrix)

An advantage of @vector<bool>@ is that it avoids the problem/incompatibility of indices in C++ starting from 0 (both ... John Abbott

14:40 Slug #701: Makefile; limit dependencies on external libs

This issue is not so important (hence priority *low*); not even sure it is worth fixing, as it may complicate the bui... John Abbott

14:37 Slug #701 (Rejected): Makefile; limit dependencies on external libs

If you have CoCoALib already (configured and) compiled, and want to repeat compilation but also including an external... John Abbott