Feature #958: New function: multiplicity and dim - CoCoALib - CoCoA Project

Feature #958

New function: multiplicity and dim

Added by Anna Maria Bigatti over 7 years ago. Updated about 2 months ago.

Status:

Resolved

Priority:

Normal

Assignee:

Anna Maria Bigatti

Category:

New Function

Target version:

CoCoALib-0.99880

Start date:

27 Oct 2016

Due date:

% Done:

80%

Estimated time:

3.00 h

Spent time:

2.50 h

Description

multiplicity and dim are implemented in cocoa-5.
Bring them to cocoalib.

The names should be MultiplicityQuot(I) and DimQuot(I) [for multiplicity(P/I) and dim(P/I) respectively]

History

#1 Updated by Anna Maria Bigatti over 7 years ago

% Done changed from 0 to 80

Done. Still need documentation.

#2 Updated by Anna Maria Bigatti over 7 years ago

Estimated time set to 3.00 h

#3 Updated by John Abbott over 7 years ago

Description updated (diff)

#4 Updated by John Abbott over 7 years ago

Status changed from New to Resolved

Do you plan to add MultiplicityQuot and DimQuot to CoCoA-5?
If one computes dim(P/I), does that actually create a new quotient ring?

#5 Updated by Anna Maria Bigatti over 7 years ago

John Abbott wrote:

Do you plan to add MultiplicityQuot and DimQuot to CoCoA-5?
If one computes dim(P/I), does that actually create a new quotient ring?

I added them to CoCoA-5 and they are used to compute dim(P/I). (approx half time)
(They do not create a quotient ring)

#6 Updated by John Abbott over 7 years ago

What exactly does multiplicity do?

I made the mistake of trying to compute multiplicity(I) instead of multiplicity(P/I); CoCoA-5 gave me an integer (not the one I expected) rather than error. Is this correct?

#7 Updated by Anna Maria Bigatti about 7 years ago

John Abbott wrote:

What exactly does multiplicity do?

I made the mistake of trying to compute multiplicity(I) instead of multiplicity(P/I); CoCoA-5 gave me an integer (not the one I expected) rather than error. Is this correct?

Yes: multiplicity is defined for a module (not yet implemented in cocoalib), so also for an ideal.