Compute f(a) = log(1 +/- exp(-a)) Numerically Optimally

Compute f(a) = log(1 +/- exp(-a)) Numerically Optimally This helper function was a directly copy from copula package. It was initialized here intend to maintain the minimum package complexity

log1mexp(a, cutoff = log(2))

Arguments

a

numeric vector of positive values

cutoff

log(2) is “optimal”, but the exact value is unimportant, and anything in (0.5, 1) is fine.