CoCoA

21 Jun 2015

21:15 CoCoA-5 Feature #737: Elementary transcendental functions (sin, cos, tan, log, exp)

JAA thinks it could occasionally be handy to have such functions available from inside CoCoA-5.
Martin gave little... John Abbott

21:12 CoCoA-5 Feature #737 (In Progress): Elementary transcendental functions (sin, cos, tan, log, exp)

Martin Kreuzer says one of his students produced a C4 package for computing approximate values of transcendental func... John Abbott

21:09 CoCoALib Bug #736: QuotientRing: is it correct to prohibit quotient by ideal(1)?

The problem arose while doing some computations for Ulrich where it was known/expected that some ideals would be @ide... John Abbott

21:06 CoCoALib Bug #736 (Closed): QuotientRing: is it correct to prohibit quotient by ideal(1)?

The quotient ring @R/I@ where @I=ideal(1)@ gives the trivial ring.
Currently the quotienting operation gives a spe... John Abbott

16 Jun 2015

08:25 CoCoALib Feature #665: Integrate Janet/Pommaret basis code

At the moment the UIBC uses only the standard algorithm to compute a Janet basis @TQBlockLow@. But it should be possi... Mario Albert

12 Jun 2015

12:03 CoCoALib Feature #664: Impl small non-prime finite fields (using logs)

Now I have a (partly?) working CoCoALib ring which wraps my previous code.
John Abbott

11 Jun 2015

20:06 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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

08:28 CoCoA-5 Feature #732 (Feedback): Primary Decomposition in CoCoA-5: port Luis Garcia's package(cocoa-4)

mostly done (with some more cleaning and testing to do) Anna Maria Bigatti

08:25 CoCoA-5 Feature #732 (Closed): Primary Decomposition in CoCoA-5: port Luis Garcia's package(cocoa-4)

Luis Garcia wrote a package for CoCoA-4. Port it to CoCoA-5. Anna Maria Bigatti

08:27 CoCoA-5 Feature #734 (Closed): Primary Decomposition in CoCoA-5: zero dimensional, zero characteristic

Anna Maria Bigatti

08:26 CoCoA-5 Feature #733 (Closed): Primary Decomposition in CoCoA-5.1.2: zero dimensional, finite characteristic

First prototype Anna Maria Bigatti

08:24 CoCoALib 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

08:23 CoCoA-5 Feature #731 (In Progress): Primary Decomposition in CoCoA-5

Implement Primary Decomposition in CoCoA-5 Anna Maria Bigatti

10 Jun 2015

17:12 CoCoALib 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 CoCoALib 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 CoCoALib 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

14:22 CoCoA-5 Bug #148: C-c C-p in emacs goes to wrong line

> *REPLY (JAA)* I think what confused me was that in the CoCoA-5 output window the cursor was at the end of the outpu... Anna Maria Bigatti

13:41 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib Feature #729 (In Progress): Betti numbers, betti diagram

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

11:46 CoCoA-5 Bug #148: C-c C-p in emacs goes to wrong line

John Abbott wrote:
> I recently tried using @C-c C-p@ and found it unhelpful; so I "stupidly" tried it a second time,... Anna Maria Bigatti

11:09 CoCoALib 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 CoCoALib 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

23:04 CoCoA-5 Bug #148: C-c C-p in emacs goes to wrong line

I recently tried using @C-c C-p@ and found it unhelpful; so I "stupidly" tried it a second time, and found that it wa... John Abbott

22:58 CoCoA-5 Bug #727 (In Progress): Emacs UI: send-file (C-c C-f) should check if buffer and file are synchronized

The emacs command @C-c C-f@ send a @source@ command to CoCoA-5, so CoCoA-5 reads the file on disk which may not be th... John Abbott

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

It has finally finished:... John Abbott

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

Progress...... John Abbott

13:19 CoCoALib 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 CoCoALib 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

22:39 CoCoA-5 Bug #726: TopLevel cannot "import" a package variable

I think a "global variable" is a reasonable design for this task.
There is a "philosophical" question: is a qualif... John Abbott

22:34 CoCoA-5 Bug #726 (Closed): TopLevel cannot "import" a package variable

I would like to have a user controllable "verbosity level" in a package. How should this be done?
I had thought o... John Abbott

02 Jun 2015

22:43 CoCoA-5 Bug #724 (In Progress): RationalSolve: wrongly complains about non zero-dim even in finite char

It is not quite as easy as I had hoped. Every so often zero polynomials pop up in awkward places (_e.g._ to be facto... John Abbott

17:06 CoCoA-5 Bug #724: RationalSolve: wrongly complains about non zero-dim even in finite char

I have disabled the zero-dimensionality check if the coeff ring is a finite field.
In one simple test that seems t... John Abbott

15:55 CoCoA-5 Bug #724: RationalSolve: wrongly complains about non zero-dim even in finite char

Is it just enough to skip the check for zero-dimensionality in this case?
(if so, that's a really simple fix)
John Abbott

15:53 CoCoA-5 Bug #724 (Closed): RationalSolve: wrongly complains about non zero-dim even in finite char

I ran the example given in issue #723 which tries to compute all rational solutions over a finite field of a homogene... John Abbott

16:35 CoCoA-5 Feature #723: Referring to indets with multiple indices from a polyring

Yes and no. I thought the topic had come up recently, but did not find it on redmine.
Perhaps the manual page for @... John Abbott

16:18 CoCoA-5 Feature #723: Referring to indets with multiple indices from a polyring

Is this what you want? (From the manual ;-)... Anna Maria Bigatti

15:45 CoCoA-5 Feature #723: Referring to indets with multiple indices from a polyring

The existing function @indets("s")@ almost does what I want except that the result is a list rather than an @INTMAP@.... John Abbott

15:39 CoCoA-5 Feature #723: Referring to indets with multiple indices from a polyring

Here is an example I want to run (NB it is very slow)... John Abbott

15:35 CoCoA-5 Feature #723 (New): Referring to indets with multiple indices from a polyring

I would like to be able to refer to multi-index indets in a poly ring using their multiple indices... where the ring ... John Abbott

13:19 CoCoA-5 Feature #719: Readline: consider creating a textual interpreter with readline

A commandline option to disable readline is probably a good idea. It is the most flexible.
You can then also add some... Christof Soeger

13:11 CoCoA-5 Feature #719: Readline: consider creating a textual interpreter with readline

I have just read some documentation for @readline@ and also looked online. We're not the first people to have proble... John Abbott

12:45 CoCoA-5 Feature #719: Readline: consider creating a textual interpreter with readline

Clearly, I was too hasty with my hack to add @readline@ :-(
I know @READLINE@ appears twice at the start -- don't ... John Abbott

12:05 CoCoA-5 Feature #719: Readline: consider creating a textual interpreter with readline

And it also works fine for me. Is it also possible to include a tab-completion? :)
Only problem is that the tests of... Christof Soeger

11:27 CoCoA-5 Feature #719: Readline: consider creating a textual interpreter with readline

My first try was not successfull. Durign the configure I got... Christof Soeger

01 Jun 2015

22:31 CoCoALib 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 CoCoALib Slug #722: valuation slow for large inputs

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

17:50 CoCoA-5 Bug #712: External Libs: missing dependencies in Makefiles

Depending on the source files would maybe be to much. It can not know how to recompile the external library.
What I ... Christof Soeger

31 May 2015

11:58 CoCoALib 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 CoCoALib 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

19:49 CoCoA-5 Feature #711: External Libs: print credits?

If we do implement some scheme for recognising use of external libraries, probably we should also do something simila... John Abbott

14:52 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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 CoCoALib 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

26 May 2015

15:51 CoCoA-5 Feature #719: Readline: consider creating a textual interpreter with readline

(I had to do a bit of updating and adaptations) it compiles and works well.
Under emacs, both in shell and in comi... Anna Maria Bigatti

25 May 2015

12:17 CoCoA-5 Feature #719: Readline: consider creating a textual interpreter with readline

Strictly the headers for @readline@ are needed only for compiling @LineProviders.C@.
Similarly @libreadline.a@ is ne... John Abbott