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PhylogeneticEM (version 1.6.0)

prod.index: Product of elements of a matrix

Description

prod.index return the product of chosen elements of a matrix.

Usage

# S3 method for index
prod(X, Id)

Value

double : the result of the product.

Arguments

X

a matrix with p rows and K column. Each row contains the number of partition in 1<=k<=K groups for one of the p children of a given node

Id

a vector of length p, result of the function xsimplex.

Details

This function is to be used in sum.simplex to be applied to all the elements given by xsimplex. Performs the product : X[1,Id[1]]*X[2,Id[2]]*...*X[p,Id[p]] if all the elements of Id are positive. Otherwise, just return 0.