log1pexp {VGAM} | R Documentation |
Computes log(1 + exp(x))
accurately.
log1pexp(x)
x |
A vector of reals (numeric).
Complex numbers not allowed since |
Computes log(1 + exp(x))
accurately.
An adjustment is made when x
is positive and large in value.
Returns log(1 + exp(x))
.
x <- c(10, 50, 100, 200, 400, 500, 800, 1000, 1e4, 1e5, 1e20, Inf) log1pexp(x) log(1 + exp(x)) # Naive; suffers from overflow x <- -c(10, 50, 100, 200, 400, 500, 800, 1000, 1e4, 1e5, 1e20, Inf) log1pexp(x) log(1 + exp(x)) # Naive; suffers from inaccuracy