CoCoA » CoCoALib

13 Jun 2017

16:37 Bug #1078 (Closed): makefile: ungraceful when interrupted

It seems that interrupting the building of @Makefile_dependencies@ gives the impression (to @make@) that the dependen... John Abbott

23 May 2017

11:32 Slug #1049: GroebnerFan: slow examples

Having 4 indets makes it easy to find "big" examples:... John Abbott

22 May 2017

14:45 Feature #813 (In Progress): Implement "elim" in CoCoALib

John Abbott wrote:
> I do not understand: "closed" but progress is 10%.
> Also your last comment suggests that ther... Anna Maria Bigatti

14:24 Feature #813: Implement "elim" in CoCoALib

I do not understand: "closed" but progress is 10%.
Also your last comment suggests that there is still some design i... John Abbott

14:10 Feature #813 (Closed): Implement "elim" in CoCoALib

There is @myElim@. Maybe I meant making a _function_?
Easy, anyway.
Anna Maria Bigatti

13:52 Feature #979: SmallestNonDivisor -- new fn

While preparing an example of a simple ideal with a big "universal denominator" I encountered a number with about 330... John Abbott

19 May 2017

15:55 Slug #1049: GroebnerFan: slow examples

... John Abbott

11:55 Bug #1069: GroebnerFan: ERROR: Matrix must be invertible

I just removed the coefficients to John's last example:... Anna Maria Bigatti

11:48 Bug #1069: GroebnerFan: ERROR: Matrix must be invertible

Just to clarify: this means that one cannot create this ring, hmmmmm....... Anna Maria Bigatti

11:45 Bug #1069: GroebnerFan: ERROR: Matrix must be invertible

Here is another "slightly smaller" matrix whose determinant is zero mod 32749:... John Abbott

11:16 Bug #1069: GroebnerFan: ERROR: Matrix must be invertible

Here is another example which gives trouble:... John Abbott

18 May 2017

21:00 Bug #1069: GroebnerFan: ERROR: Matrix must be invertible

Here are some order matrices with not-too-big entries whose det is a multiple of 32749:... John Abbott

17 May 2017

18:02 Slug #1057: Slug: Polynomial ring contructor slow with (big) matrix ordering

... Anna Maria Bigatti

10:39 Slug #1057 (In Progress): Slug: Polynomial ring contructor slow with (big) matrix ordering

First problem found: @NewOrdvArith(ord)@ ic computed twice.
If @ord@ is defined by M, then many checks are done on M. Anna Maria Bigatti

15:52 Bug #1069: GroebnerFan: ERROR: Matrix must be invertible

John Abbott wrote:
> Another approach would be to persuade GFan to produce matrices with smaller entries... this is ... Anna Maria Bigatti

15:46 Bug #1069: GroebnerFan: ERROR: Matrix must be invertible

Another approach would be to persuade GFan to produce matrices with smaller entries... this is probably not so easy! John Abbott

15:45 Bug #1069 (In Progress): GroebnerFan: ERROR: Matrix must be invertible

The correct solution would be to have a proper implementation of matrix orderings without any "tricks" (too bad if it... John Abbott

15:39 Bug #1069: GroebnerFan: ERROR: Matrix must be invertible

John Abbott wrote:
> Here is a guess as to what the problem is... for matrix orderings there was some "funny trick" ... Anna Maria Bigatti

15:18 Bug #1069: GroebnerFan: ERROR: Matrix must be invertible

Here is a guess as to what the problem is... for matrix orderings there was some "funny trick" using a matrix reduced... John Abbott

15:09 Bug #1069: GroebnerFan: ERROR: Matrix must be invertible

Another smaller example (but not as small as Anna's)... John Abbott

14:29 Bug #1069: GroebnerFan: ERROR: Matrix must be invertible

Smaller example, but still too big... Anna Maria Bigatti

11:37 Bug #1069 (In Progress): GroebnerFan: ERROR: Matrix must be invertible

The following causes an error:... John Abbott

13:47 Slug #1070: Slug: MakeTermOrd (rk calls in RemoveRedundantRows)

I just implemented a workaround:
I check det(M) before calling @RemoveRedundantRows@, if not 0 return M.
Anna Maria Bigatti

13:45 Slug #1070 (New): Slug: MakeTermOrd (rk calls in RemoveRedundantRows)

The function @RemoveRedundantRows@ is quite slow because of the repeated calls to @rk@.
I had thought it was not imp... Anna Maria Bigatti

13:40 Design #854: Function MakeTermOrd should be renamed MakeTermOrdMat?

Now I'm more inclined to keep @MakeTermOrd@ for CoCoA-5.
Possibly make a distinction in CoCoALib (where mat and ord ... Anna Maria Bigatti