Opened 10 years ago

Last modified 9 years ago

#454 new proposed feature

extend proc changevar and others for rings with minpoly

Reported by: gorzel Owned by: somebody
Priority: minor Milestone: Release 4-0-0
Component: singular-libs Version: 3-1-6
Keywords: Cc:

Description (last modified by gorzel)

The proc changeord et al will also work for baserings with algebraic extension, if it keeps the minpoly.

Could somebody add this line 

   if (minpoly!=0) { @newring = @newring + "minpoly = " + string(minpoly)+";";}

to the procs changeord, changevar, and extendring preceeding the line with execute(@newring);

Compare with the attached file ringwithmipo.lib

The proc changechar also forgets the minpoly, but keeping the minpoly may cause a crash with factorize if the minpoly becomes reducible in the new ring, so some warning may be useful there.

Attachments (1)

ringwithmipo.lib​ (28.7 KB) - added by gorzel 10 years ago.

Download all attachments as: .zip

Change History (4)

Changed 10 years ago by gorzel

Attachment: ringwithmipo.lib​ added

comment:1 Changed 10 years ago by gorzel

Summary: extend proc changevar and for rings with minpoly → extend proc changevar and others for rings with minpoly

comment:2 Changed 10 years ago by mlee

Owner: changed from somebody to hannes

comment:3 Changed 9 years ago by gorzel

Description: modified (diff)
Milestone: 3-1-6 and higher → Release 4-0-0
Owner: changed from hannes to somebody
Version: 3-1-5 → 3-1-6

Reminder:

I know that the usage of execute should be avoided and better replaced by the ringlist command, but the ring.lib uses at many places 'execute' to keep the minpoly while making a ring change.

Nonetheless in some cases the minpoly gets lost and these cases have not yet been fixed as a I suggested.

(The simple solution would really by sufficient to make it work.)

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