durmod (version 1.1-4)

a2p: Convert probability parameters to probabilities

Description

mphcrm parametrizes the probabilities that it optimizes. For \(n+1\) probabilities there are \(n\) parameters \(a_j\), such that probability \(P_i = \frac{a_i}{\sum_j \exp(a_j)}\), where we assume that \(a_0 = 0\).

Usage

a2p(a)
p2a(p)

Arguments

a

a vector of parameters

p

a vector of probabilities with sum(p) = 1

Value

a2p returns a vector probabilities with sum 1.

p2a returns a vector of parameters.

Examples

# NOT RUN {
# Draw 5 parameters
a <- rnorm(5)
a
# make 6 probabilities
p <- a2p(a)
p
# convert back
p2a(p)
# }