log(1 + exp(x)), without overflow for large x and accurate for very negative x.
Not an R function. R has it only in its C API (Rmath.h), as log1pexp; the DPQ package also has it.
Parameters
x: number
A number.
Returns number
log(1 + exp(x)); 0 at x = -Infinity, Infinity at x = Infinity.
log(1 + exp(x)), without overflow for large x and accurate for very negative x. Not an R function. R has it only in its C API (Rmath.h), as
log1pexp; the DPQ package also has it.