trums
    GDn  - drop dimension n in 3-d and 4-d output
    Gh   - hyperplane intersections
    Gi   - inner planes only
     Gn  -  no planes
     Go  -  outer planes only
    Gr   - ridges
    Gt   - transparent outer ridges to view 3-d Delaunay

Print options:
    PAn  - keep n largest Delaunay regions by area
    Pdk:n - drop facet if normal[k] <= n (default 0.0)
    PDk:n - drop facet if normal[k] >= n
    PFn  - keep Delaunay regions whose area is at least n
    Pg   - print good Delaunay regions (nee