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Feature #1652

Add LM to cocoalib ?

Added by Florian Walsh over 2 years ago. Updated 2 months ago.

Status:
In Progress
Priority:
Low
Assignee:
-
Category:
New Function
Target version:
CoCoALib-0.99900
Start date:
26 Jan 2022
Due date:
% Done:

10%

Estimated time:
Spent time:
0.55 h

Description

To compute the leading monomial of a polynomial in cocoalib I need to call 

monomial(owner(f), LC(f), LPP(f));

This seems a bit complicated to me.

Related issues

Related to CoCoALib - Support #1664: geobucket: documentationNew2022-02-14

History

#1 Updated by Anna Maria Bigatti about 2 years ago

  • Category set to New Function
  • % Done changed from 0 to 10

The reason why we do not have LM in cocoalib is that we prefer not to make it handy ;-)

Sounds like a joke, but this function is expensive (creates memory and makes copy), and one might use it in a 1000000-cycle loop as an alternative to LT or LC (just pointers).

The temptation of writing something like f -LM(f) could be quite high as well.

So we wrote functions like
MoveLMToFront(f,g), MoveLMToBack(f,g), DivLM,
f.myAddMulLM, f.myDeleteLM, ...
to do what we need to do, without useless creating/copying.

Are these covering all plausible needs? probably not: what do you need?
Are these documented? ... ehm ... not yet.

#2 Updated by Florian Walsh about 2 years ago

That makes sense. I was implementing DivAlg which seems to exist only in a cocoa package.
I should probably use the geobucket functions instead.
The title "geobucket" is a bit obscure in my opinion. I would have never searched in that section of the documentation for reducing polynomials.

#3 Updated by John Abbott about 2 years ago

  • Target version set to CoCoALib-0.99850

We really need to come up with a way of making the CoCoALib documentation friendlier.
I am reasonably happy with how the CoCoA-5 online manual works, so we could aim to imitate
that (incl putting in keywords).

Exactly how we could make geobuckets more comprehensible is not yet clear to me.

#4 Updated by Anna Maria Bigatti about 2 years ago

Florian Walsh wrote:

That makes sense. I was implementing DivAlg which seems to exist only in a cocoa package.

I believe I wrote it: certainly I wrote NR, which can be easily generalized.
I'll check tomorrow morning.

#5 Updated by John Abbott about 2 years ago

#6 Updated by John Abbott about 2 years ago

  • Status changed from New to In Progress

Any progress to report here? Also Gereon Kremer is hoping to use DivAlg.
It is surprising that it is (apparently) not implemented in CoCoALib.
Perhaps too much to ask for 0.99800, but may be possible for 0.99801?
It'd be good to have it soon.

#7 Updated by John Abbott 2 months ago

  • Target version changed from CoCoALib-0.99850 to CoCoALib-0.99900

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