CoCoA

07 May 2016

13:59 CoCoA-5 Feature #876: subst: allowed also for indets in the coeff ring

Here is an example I was trying with Sandro Logar... John Abbott

13:57 CoCoA-5 Feature #876 (New): subst: allowed also for indets in the coeff ring

Suppose we have a poly ring of the form @QQ(a,b)[x,y]@ and I want to substitute @b=a+1@.
Currently @subst@ refuses b... John Abbott

06 May 2016

16:43 CoCoALib Slug #866: implicit, ImplicitHypersurface: improve output verification

I have not yet had time to look at your horner code. Anyway, I would expect it work fairly well provided the "variab... John Abbott

03 May 2016

17:02 CoCoA-5 Slug #875: Interpreter is too slow reading a big polynomial

I have tried doing some profiling. The interpreter takes quadratic time (in the number of terms) to read a polynomia... John Abbott

14:00 CoCoA-5 Slug #875 (In Progress): Interpreter is too slow reading a big polynomial

I'm trying to read a large polynomial: about 6Mbytes, about 127000 terms in 100 indets, coefficients in @QQ@ (but all... John Abbott

13:14 CoCoALib Slug #874: factor: too slow on largish multivariate poly

Mario has just sent me an even bigger polynomial to try: 100 indets, about 127000 terms, total degree 9.
He also m... John Abbott

10:50 CoCoALib Slug #874 (In Progress): factor: too slow on largish multivariate poly

Computing all contents takes about 44s; and computing contents wrt all indets which appear just linearly takes about ... John Abbott

10:42 CoCoALib Slug #874: factor: too slow on largish multivariate poly

Mario has given me an example poly. The poly ring has 84 indets; the poly itself uses 69 indets, and has about 6800 ... John Abbott

10:37 CoCoALib Slug #874 (In Progress): factor: too slow on largish multivariate poly

Mario generates lots of multivariate polys (over @QQ@); most of them are irreducible. He reports that factorization ... John Abbott

10:34 CoCoALib Support #861 (In Progress): Janet basis code: TmpJB files give some problems with C++11 (using CLANG/LLVM)

Mario has given me an updated version of his code. He has used the @__cplusplus@ preprocessor variable to have code ... John Abbott

29 Apr 2016

22:00 CoCoALib Feature #873: bool3: add some logical operations?

(Maybe this is what you had in mind from the beginning)
I think the only safe definition for @and3@ is the @and@ bet... Anna Maria Bigatti

19:21 CoCoALib Feature #873: bool3: add some logical operations?

The "monomial generators" case is easy.
The "is a monomial ideal" is hard in any case: even if both ideals are not m... John Abbott

18:53 CoCoALib Feature #873: bool3: add some logical operations?

I expect in some cases we want
uncertain3 and false3 = false3 (sum of ideals has monomial generators)
and other t... Anna Maria Bigatti

18:15 CoCoALib Feature #873 (In Progress): bool3: add some logical operations?

It would not be harmful to your code if @bool3@ offered the functions, but you may be right that it would not simplif... John Abbott

28 Apr 2016

10:45 CoCoALib Feature #873: bool3: add some logical operations?

I'm against this idea. Indeed it might be handy, but dangerous as well: while working on fixing a bug on the bool3 f... Anna Maria Bigatti

27 Apr 2016

19:05 CoCoA-5 Bug #870: GBasis of product of ideals is wrong (Vadim Tropashko) --> I.myReset()

I have added a new CoCoALib test (@test-bug6.C@) which tests for this specific problem.
It should later be expande... John Abbott

08:57 CoCoA-5 Bug #870: GBasis of product of ideals is wrong (Vadim Tropashko) --> I.myReset()

John Abbott wrote:
> I suggest that Anna try to fix the functions already in @SparsePolyRing.C@.
done! (cvs-ing)
... Anna Maria Bigatti

18:49 CoCoALib Feature #873: bool3: add some logical operations?

BOOST also offers a "not" operation. It would be trivial to implement @not3@ (giving value 1 - arg).
If we do off... John Abbott

18:45 CoCoALib Feature #873: bool3: add some logical operations?

Part of the motivation comes from Anna's rectification of code for ideal arithmetic (see issue #870).
For example ... John Abbott

18:42 CoCoALib Feature #873: bool3: add some logical operations?

I suggest adding the following two operations:
* *and* which is equivalent to "minimum"
* *or* which is equivalent... John Abbott

18:37 CoCoALib Feature #873 (In Progress): bool3: add some logical operations?

Currently there are no logical operations on @bool3@ values.
Discuss whether it may be helpful to include some sim... John Abbott

26 Apr 2016

19:05 CoCoALib Feature #872 (In Progress): LinSolve for matrices over FFp

Currently CoCoALib uses generic code for solving linear systems over small finite fields.
Implement some special c... John Abbott

15:19 CoCoA-5 Bug #870: GBasis of product of ideals is wrong (Vadim Tropashko) --> I.myReset()

I suggest that Anna try to fix the functions already in @SparsePolyRing.C@.
Even though I'm hoping for a proper re... John Abbott

13:38 CoCoA-5 Bug #870: GBasis of product of ideals is wrong (Vadim Tropashko) --> I.myReset()

I continue to think that the current design of ideals is completely wrong (but I cannot find the redmine task about t... John Abbott

10:16 CoCoA-5 Bug #870 (In Progress): GBasis of product of ideals is wrong (Vadim Tropashko) --> I.myReset()

Here is the equivalent CoCoALib code -- it exhibits the problem.... John Abbott

09:39 CoCoA-5 Bug #870: GBasis of product of ideals is wrong (Vadim Tropashko) --> I.myReset()

Try looking around @SparsePolyRing.C:2029@
John Abbott

09:35 CoCoA-5 Bug #870: GBasis of product of ideals is wrong (Vadim Tropashko) --> I.myReset()

Since this was reported by a CoCoA-5 user i have put it in the CoCoA-5 category even though I'm almost certain that t... John Abbott

09:31 CoCoA-5 Bug #870 (Closed): GBasis of product of ideals is wrong (Vadim Tropashko) --> I.myReset()

Vadim Tropashko reported an incorrect result. Robbiano has simplified it. Here is the simplified version.... John Abbott

15:01 CoCoALib Design #871 (New): Redesign ideals

Review the design of ideals.
Some points to bear in mind:
* an ideal should probably be immutable -- any operatio... John Abbott

22 Apr 2016

18:09 CoCoALib Slug #866: implicit, ImplicitHypersurface: improve output verification

I checked in @IsZeroEvalHorner@ in case you want to play with it.
The call is currently commented out. Just look fo... Anna Maria Bigatti

18:01 CoCoALib Slug #866: implicit, ImplicitHypersurface: improve output verification

Anna Maria Bigatti wrote:
> > But I'd like another try: I'm planning to try to implement a sort of recursive Horner.... Anna Maria Bigatti

17:02 CoCoALib Slug #866: implicit, ImplicitHypersurface: improve output verification

I seem to recall vaguely seeing a paper by Mourrain (or someone in his group) possibly about this. I think the quest... John Abbott

16:26 CoCoALib Slug #866: implicit, ImplicitHypersurface: improve output verification

Anna Maria Bigatti wrote:
> But I'd like another try: I'm planning to try to implement a sort of recursive Horner. M... Anna Maria Bigatti

15:14 CoCoALib Feature #869 (New): SmallFpImpl: different repr for computation and for storage?

I would like to use @unsigned short@ to store @SmallFp@ values, but still have a decent range _i.e._ without the rest... John Abbott

19 Apr 2016

14:59 CoCoALib Bug #867: Compilation Error: C++11 and old GMP-Version

Perhaps I should have read the @configure@ script better: I have already inserted (ages ago) a warning for versions o... John Abbott

14:54 CoCoALib Bug #867: Compilation Error: C++11 and old GMP-Version

John Abbott wrote:
> Mario suggested that we could modify the CoCoALib configuration script to check that GMP is at ... Anna Maria Bigatti

14:20 CoCoALib Bug #867 (In Progress): Compilation Error: C++11 and old GMP-Version

Mario suggested that we could modify the CoCoALib configuration script to check that GMP is at least version 5.0.0; c... John Abbott

14:27 CoCoALib Feature #82 (In Progress): C++11 compatibility questions

Mario has found a web page which explains that the preprocessor flag @__cpluscplus@ has a numerical value indicating ... John Abbott

18 Apr 2016

12:38 CoCoA-5 Design #868: Der, Bin: why the capital letter?

It is also the case for @bin@.
In CoCoALib they are called @deriv@ and @binomial@, so the lower-case name is differe... Anna Maria Bigatti

12:33 CoCoALib Slug #866: implicit, ImplicitHypersurface: improve output verification

John Abbott wrote:
> I suggest adding a probabilistic check of correctness: use the parametric formulas to generate ... Anna Maria Bigatti

12:23 CoCoALib Slug #866: implicit, ImplicitHypersurface: improve output verification

I suggest adding a probabilistic check of correctness: use the parametric formulas to generate a random (numerical) p... John Abbott

17 Apr 2016

20:06 CoCoA-5 Bug #287: --fullCoCoALibError prints too much (Try/UponError)

I still like my proposal in comment 2. How easy it will be to implement is not clear to me.
Anyway the implementa... John Abbott

20:00 CoCoA-5 Design #868: Der, Bin: why the capital letter?

I understand we want to keep @Der@ for backward compatibility.
Since we have @deg@, @den@, @det@ why not also @der... John Abbott

19:59 CoCoA-5 Design #868 (Closed): Der, Bin: why the capital letter?

In CoCoA-5 the function for computing formal derivatives is @Der@; why does @der@ not exist?
John Abbott

14 Apr 2016

18:00 CoCoA-5 Bug #287: --fullCoCoALibError prints too much (Try/UponError)

Ooops, apparently I released the Mac version of cocoa-5.1.4 with the flag activated.
This means that users computing... Anna Maria Bigatti

13 Apr 2016

17:04 CoCoALib Slug #866: implicit, ImplicitHypersurface: improve output verification

John Abbott wrote:
> The example below takes about 12s on my computer, but only about 0.25s if the coeff field is @Z... Anna Maria Bigatti

15:45 CoCoALib Slug #866 (In Progress): implicit, ImplicitHypersurface: improve output verification

The example below takes about 12s on my computer, but only about 0.25s if the coeff field is @ZZ/(32003)@. Why is it... John Abbott

13:34 CoCoALib Slug #866 (In Progress): implicit, ImplicitHypersurface: improve output verification

The current impl of @SliceCoreQQ@ is simple rather than efficient.
It uses modular+CRT to build the answer.
Current... John Abbott

15:41 CoCoALib Bug #867: Compilation Error: C++11 and old GMP-Version

Thanks to Anna (grrrr!) you can build CoCoALib (and CoCoA-5) with an uninstalled version of GMP, _i.e._ a "private" v... John Abbott

15:23 CoCoALib Bug #867 (Closed): Compilation Error: C++11 and old GMP-Version

I tried to compile CoCoALib at our LinuxCluster with a pretty old GMP version (4.3.1) and C++11 activated (with addit... Mario Albert

13:22 CoCoA-5 Feature #865 (New): Implicit: make easier to use with rational functions

Make the CoCoA-5 interface (also CoCoALib interface?) easier to use when the parametric descriptions are as rational ... John Abbott