The dimension of a normal toric variety equals the dimension of its dense algebraic torus. In this package, the fan associated to a normal $d$-dimensional toric variety lies in the rational vector space $\QQ^d$ with underlying lattice $N = \ZZ^d$. Hence, the dimension simply equals the number of entries in a minimal nonzero lattice point on a ray.
The following examples illustrate normal toric varieties of various dimensions.
i1 : dim toricProjectiveSpace 1 o1 = 1 |
i2 : dim affineSpace 2 o2 = 2 |
i3 : dim toricProjectiveSpace 5 o3 = 5 |
i4 : dim hirzebruchSurface 7 o4 = 2 |
i5 : dim weightedProjectiveSpace {1,2,2,3,4}
o5 = 4
|
i6 : X = normalToricVariety ({{4,-1,0},{0,1,0}},{{0,1}})
o6 = X
o6 : NormalToricVariety
|
i7 : dim X o7 = 3 |
i8 : isDegenerate X o8 = true |
In this package, number of entries in any ray equals the dimension of both the underlying lattice and the normal toric variety, so this method does essentially no computation.