Project

General

Profile

Feature #1122

New fn: RandomLinearForm

Added by John Abbott 6 months ago. Updated 7 days ago.

Status:
Feedback
Priority:
Normal
Category:
CoCoA-5 function: new
Target version:
Start date:
15 Nov 2017
Due date:
% Done:

80%

Estimated time:
Spent time:

Description

Should we add a new function RandomLinearForm?

What should its arg(s) be?

Split off from issue #1067.


Related issues

Related to CoCoA-5 - Design #1067: "Randomize" and "Randomized" obsolete?Closed2017-05-14

Related to CoCoALib - Feature #1169: New function: RandomLinearForm (CoCoALib)Resolved2018-03-19

History

#1 Updated by John Abbott 6 months ago

  • Related to Design #1067: "Randomize" and "Randomized" obsolete? added

#2 Updated by Anna Maria Bigatti 2 months ago

  • Related to Feature #1169: New function: RandomLinearForm (CoCoALib) added

#3 Updated by Anna Maria Bigatti 2 months ago

  • Status changed from New to Feedback
  • Assignee set to Anna Maria Bigatti
  • % Done changed from 0 to 80

Implemented in CoCoALib. See Feature #1169

#4 Updated by John Abbott 7 days ago

I have just tried calling RandomLinearForm with a large ring containing 10000 indets; it took 1 minute, which is SLOW.
Why?

NOTE Ouch! I have just tried the same but with a ring containing 5000 indets; it took 8s. This suggests CUBIC COMPLEXITY??? There must be something wrong!

#5 Updated by John Abbott 7 days ago

I have reversed the loop in RandomLinearForm (in SparsePolyRing.C). Now it is significantly faster.

But why was it so slow before; I thought we handled specially that case... evidently not :-(

Maybe we could use PushBack??

#6 Updated by Anna Maria Bigatti 7 days ago

John Abbott wrote:

Maybe we could use PushBack??

Depends on the ordering :-(
But we could make special implementations for (deg)lex and degrevlex

Also available in: Atom PDF