Message-ID: <CAML4n3NUKBMtXSt=naEktP4udKruenhG9N-Kdyx=sjpcx-BXvA@mail.gmail.com>
Date: 2016-09-09T17:24:32Z
From: Hans W Borchers
Subject: Different results for tan(pi/2) and tanpi(1/2)
As the subject line says, we get different results for tan(pi/2) and
tanpi(1/2), though this should not be the case:
> tan(pi/2)
[1] 1.633124e+16
> tanpi(1/2)
[1] NaN
Warning message:
In tanpi(1/2) : NaNs produced
By redefining tanpi with sinpi and cospi, we can get closer:
> tanpi <- function(x) sinpi(x) / cospi(x)
> tanpi(c(0, 1/2, 1, 3/2, 2))
[1] 0 Inf 0 -Inf 0
Hans Werner