ApCoCoA-1:FGLM.FGLM

From ApCoCoAWiki
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.
This article is about a function from ApCoCoA-1.

FGLM.FGLM

Performs a FGLM Groebner Basis conversion using ApCoCoAServer.

Syntax

FGLM(GBInput:LIST, M:MAT):LIST
FGLM(GBInput:LIST):LIST

Description

Please note: The function(s) explained on this page is/are using the ApCoCoAServer. You will have to start the ApCoCoAServer in order to use it/them.

The function FGLM calls the ApCoCoAServer to perform a

FGLM Groebner Basis conversion. Please note that the ideal generated by

the given Groebner Basis must be zero-dimensional. The Groebner Basis contained in list GBInput will be converted into a Groebner Basis with respect to term ordering Ord(M), i.e. M must be a matrix specifying a term ordering. If the parameter M is not specified, ApCoCoA will assume M = Ord(). Please note that the resulting polynomials belong to a different ring than the ones in GBInput.

The return value will be the transformed Groebner basis polynomials.

  • @param GBInput A Groebner basis of a zero-dimensional ideal.

  • @return A Groebner basis of the ideal generated by the polynomials of GBInput. The polynomials of the new Groebner basis will belong to the polynomial ring with term ordering specified by M or Ord() in case M is not given.

The following parameter is optional.

  • @param M A matrix representing a term ordering.

Example

Use QQ[x, y, z], DegRevLex;
GBInput := [z^4 -3z^3 - 4yz + 2z^2 - y + 2z - 2, yz^2 + 2yz - 2z^2 + 1, y^2 - 2yz + z^2 - z, x + y - z];
M := LexMat(3);
GBNew := FGLM.FGLM(GBInput, M);
Use QQ[x, y, z], Ord(M);
-- New basis (Lex)
BringIn(GBNew);

-------------------------------
[z^6 - z^5 - 4z^4 - 2z^3 + 1, y - 4/7z^5 + 5/7z^4 + 13/7z^3 + 10/7z^2 - 6/7z - 2/7,
 x + 4/7z^5 - 5/7z^4 - 13/7z^3 - 10/7z^2 - 1/7z + 2/7]
-------------------------------

GBasis5, and more

Introduction to CoCoAServer