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D.13.6.13 tInitialForm

Procedure from library tropical.lib (see tropical_lib).

Usage:
tInitialForm(f,w); f a polynomial, w an integer vector

Assume:
f is a polynomial in Q[t,x_1,...,x_n] and w=(w_0,w_1,...,w_n)

Return:
poly, the t-initialform of f(t,x) w.r.t. w evaluated at t=1

Note:
the t-initialform is the sum of the terms with MAXIMAL
weighted order w.r.t. w

Example:
 
LIB "tropical.lib";
==> Welcome to polymake version
==> Copyright (c) 1997-2015
==> Ewgenij Gawrilow, Michael Joswig (TU Darmstadt)
==> http://www.polymake.org
ring r=0,(t,x,y),dp;
poly f=t4x2+y2-t2xy+t4x-t9;
intvec w=-1,-2,-3;
tInitialForm(f,w);
==> y2+x