monjMult -- j-multiplicity of a monomial ideal

Synopsis

• Usage:

  monjMult I

• Inputs:
  • I, an ideal,
• Outputs:
  • an integer, the j-multiplicity of I.

Description

i1 : R = QQ[x,y]

o1 = R

o1 : PolynomialRing

i2 : I = (ideal"xy5,x2y3,x3y2")^4

             4 20   5 18   6 17   6 16   7 15   8 14   7 14   8 13   9 12 
o2 = ideal (x y  , x y  , x y  , x y  , x y  , x y  , x y  , x y  , x y  ,
     ------------------------------------------------------------------------
      10 11   8 12   9 11   10 10   11 9   12 8
     x  y  , x y  , x y  , x  y  , x  y , x  y )

o2 : Ideal of R

i3 : elapsedTime monjMult I
 -- 0.44581 seconds elapsed

o3 = 192

i4 : elapsedTime jMult I
 -- 3.79924 seconds elapsed

o4 = 192

See also

• multiplicitySequence -- the multiplicity sequence of an ideal
• jMult -- the j-multiplicity of an ideal
• monReduction -- the minimal monomial reduction of a monomial ideal
• NP -- the Newton polyhedron of a monomial ideal