next | previous | forward | backward | up | top | index | toc | Macaulay2 website
AssociativeAlgebras :: ncHilbertSeries

ncHilbertSeries -- Computes the Hilbert series of a noncommutative ring

Synopsis

Description

This method computes the Hilbert series of a graded noncommutative ring. If the ring is defined over a field (and potentially not standard graded), then a basis is computed and the generating function of the degrees of that basis is returned. The degree to which one computes the Hilbert series is controlled with the Order option. The output is returned as either an expression (if a rational representation can be found using toRationalFunction) or as an element of the degreesRing of the input.

i1 : A = QQ<|x,y,z|>

o1 = A

o1 : FreeAlgebra
i2 : ncHilbertSeries(A,Order=>10)

        1
o2 = ------
     1 - 3T

o2 : Expression of class Divide
i3 : A = QQ<|x,y,z,Degrees=>{1,2,3}|>

o3 = A

o3 : FreeAlgebra
i4 : ncHilbertSeries(A,Order=>10)

             1
o4 = -----------------
               2    3
     1 - (T + T  + T )

o4 : Expression of class Divide
i5 : B = threeDimSklyanin(QQ,{1,1,-1},{x,y,z})

o5 = B

o5 : FreeAlgebraQuotient
i6 : ncHilbertSeries(B,Order=>10)

         1
o6 = --------
            3
     (1 - T)

o6 : Expression of class Divide

Ways to use ncHilbertSeries :

For the programmer

The object ncHilbertSeries is a method function with options.