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:
  • S, an instance of the type DualSpace,

Description

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