next | previous | forward | backward | up | top | index | toc | Macaulay2 website
PhylogeneticTrees :: pRing

pRing -- construct the ring of probability coordinates



The probability coordinates for a phylogenetic tree model have one coordinate for each possible outcome of the model. A possible outcome is any labeling of the leaves of the tree by elements of the group $G$ of the model. Thus the number of coordinates is $|G|^n$ where $n$ is the number of leaves.

A variable name for the ring can be passed using the optional argument Variable. Otherwise the symbol p is used.

i1 : pRing(4,CFNmodel)

o1 = QQ[p       ..p       ]
         0,0,0,0   1,1,1,1

o1 : PolynomialRing
i2 : pRing(3,JCmodel)

o2 = QQ[p     ..p     ]
         0,0,0   3,3,3

o2 : PolynomialRing

See also

Ways to use pRing :

For the programmer

The object pRing is a method function with options.