RingElement

RingElement _ ZZ

Synopsis:

Usage: g = f_d

Operator: _

Input:

f, an instance of class RingElement: a polynomial

d, an instance of class ZZ.

Output:

g, an instance of class RingElement: the sum of those terms of f whose total degree is d.

See also:

RingElement _ {...}

Code:

     -- ../../../Macaulay2/m2/enginering.m2:208-212
     RingElement _ ZZ := RingElement => (f,d) -> (
          u := select(terms f, t -> d === sum degree t);
          if #u === 0 then 0_(ring f)
          else sum u
          )