Computes log(1 + x) for small x.
A scalar, series or table.
A scalar, series, or table.
log(1 + 1e-17)
exp(log(1 + 1e-17)) - 1
For real values, LOG1P is accurate for small x where 1 + x == 1 for double precision accuracy.
For small x, LOG1P(x) is approximately x, but LOG(1 + x) is approximately 0 for double precision accuracy.
See EXPM1 to compute EXP(x) - 1 for small x, the inverse of LOG1P.