sum.simplex returns the sum on k_1+...+k_p=K, k_i>0 of the products
of NN[i,k_i].
Usage
"sum"(NN, K, p)
Arguments
NN
a martix with p rows and K column. Each row contains the number of
partition in 1
K
an integer. Tne number of groups wanted.
p
an integer. The number of daughters of a node.
Value
double : the result of the sum.
Details
This function uses xsimplex to perform the product of NN[i,k_i] for
all combination of k_i such that k_1+...+k_p=K, k_i>0, using function
prod.index. Then sum all the products.