Package sagbi/SB.GetTruncDeg
From ApCoCoAWiki
| This article is about a function from ApCoCoA-2. |
SB.GetTruncDeg
This function returns the truncation degree of the currently stored SAGBI basis in the given subalgebra.
Syntax
SB.GetTruncDeg(S: TAGGED("$apcocoa/sagbi.Subalgebra")): INT
Description
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@param S A subalgebra
@return 0 if there is no (truncated) SAGBI basis stored in S, -1 if there is a complete SAGBI basis stored in S and d if there is a d-truncated SAGBI basis stored in S.
Example
Use R ::= QQ[x,y]; fs := [x^2*y, x^2 -y^2, x^2*y^2 -y^4, x^2*y^4]; S := SB.Subalgebra(R,fs); PrintLn SB.GetTruncDeg(S); -- 0 PrintLn SB.GetTruncSAGBI(ref S,4); -- [x^2 -y^2, x^2*y, x^2*y^2 -y^4] PrintLn SB.GetTruncDeg(S); -- 4 PrintLn SB.GetSAGBI(ref S); -- [x^2 -y^2, x^2*y, x^2*y^2 -y^4, y^6, x^2*y^4] PrintLn SB.GetTruncDeg(S); -- -1
See also
Package sagbi/SB.GetTruncSAGBI
