Function builtin_log1p 

fn builtin_log1p(
    args: &[RValue],
    _: &[(String, RValue)],
) -> Result<RValue, RError>

Numerically stable log(1 + x).

More accurate than log(1 + x) for x near zero, where catastrophic cancellation would otherwise lose precision.

@param x numeric vector with values > -1 @return numeric vector of log(1 + x)