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

## Synopsis

• Function: truncate
• Usage:
S = truncate(T, d)
• Inputs:
• T, an instance of the type DualSpace, or an instance of the type PolySpace
• d, an integer, the degree bound for the designated variables
• Outputs:

## Description

This method truncates a dual space or polynomial space T so that the total degree of all terms does not exceed d.

 i1 : R = CC[x,y]; i2 : I = ideal {x-y}; o2 : Ideal of R i3 : D = truncatedDual(origin R, I, 5) o3 = | 1 x+y .5x2+xy+.5y2 .166667x3+.5x2y+.5xy2+.166667y3 .0416667x4+.166667x3y+.25x2y2+.166667xy3+.0416667y4 .00833333x5+.0416667x4y+.0833333x3y2+.0833333x2y3+.0416667xy4+.00833333y5 | o3 : DualSpace i4 : truncate(D, 3) o4 = | x3+3x2y+3xy2+y3 x2+2xy+y2 x+y 1 | o4 : DualSpace