truncate(DualSpace,List,ZZ) -- truncate a polynomial space or dual space

Synopsis

Function: truncate
Usage:

S = truncate(T, v, d)
Inputs:
- T, an instance of the type DualSpace, or an instance of the type PolySpace
- v, a list, a list of the integers designating which variables to bound
- d, an integer, the degree bound for the designated variables
Outputs:
- S, an instance of the type DualSpace,

This method truncates a dual space or polynomial space T, so that the total degree of the specified variables is bounded by d.

i1 : R = CC[x,y];

i2 : I = ideal {x,y};

o2 : Ideal of R

i3 : D = zeroDimensionalDual(origin R, I^3)

o3 = | 1 y x .5y2 xy .5x2 |

o3 : DualSpace

i4 : truncate(D, {0}, 1)

o4 = | xy x y2 y 1 |

o4 : DualSpace