G = gfanInitialForms(L,W)
G = gfanInitialForms(I,W)
H = gfanInitialForms(M,W)
This method gives the initial forms of a list of polynomials. If the "ideals" option is used, generators for the initial ideal are given. If the "pair" option is used, then the output is a pair of MarkedPolynomialLists.






gfan Documentation This program converts a list of polynomials to a list of their initial forms with respect to the vector given after the list.Options:ideal: Treat input as an ideal. This will make the program compute the initial ideal of the ideal generated by the input polynomials. The computation is done by computing a Groebner basis with respect to the given vector. The vector must be positive or the input polynomials must be homogeneous in a positive grading. None of these conditions are checked by the program.pair: Produce a pair of polynomial lists. Used together with ideal this option will also write a compatible reduced Groebner basis for the input ideal to the output. This is useful for finding the Groebner cone of a nonmonomial initial ideal.mark: If the pair option is and the ideal option is not used this option will still make sure that the second output basis is marked consistently with the vector.list: Read in a list of vectors instead of a single vector and produce a list of polynomial sets as output.
The object gfanInitialForms is a method function with options.