The R Project SVN R

R : Copyright 1998, The R Development Core Team
Version 0.63.0 Unstable (June 23, 1998)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type    "?license" or "?licence" for distribution details.

R is a collaborative project with many contributors.
Type    "?contributors" for a list.

Type    "demo()" for some demos, "help()" for on-line help, or
    "help.start()" for a HTML browser interface to help.
Type    "q()" to quit R.

> ##-- These should all return  'TRUE'
> 
> all(1:12 == cumsum(rep(1,12)))
[1] TRUE
> 
> x <- rnorm(127); sx <- sum(x);  abs((sum(rev(x)) -sx)) < 1e-12 * abs(sx)
[1] TRUE
> 
> typeof(1:4) == "integer" #-- fails for 0.2, 0.3,.., 0.9
[1] TRUE
> 
> all((0:6) == pi + ((-pi):pi))
[1] TRUE
> all((0:7) == (pi+seq(-pi,pi, len=8))*7/(2*pi))
[1] TRUE
> 
> ## This should be symmetric !!
> cc <- c(1:10,10:1) ;      all(cc == rev(cc))
[1] TRUE
> ##nomore:
> ##cc <- convolve(cc, c(1,2,1));   all(cc == rev(cc))
> 
> ## Real Trig.:
> cos(0) == 1
[1] TRUE
> sin(3*pi/2) == cos(pi)
[1] TRUE
> x <- rnorm(99)
> all( sin(-x) == - sin(x))
[1] TRUE
> all( cos(-x) == cos(x))
[1] TRUE
> 
> x <- 1:99/100
> all(abs(1 - x / asin(sin(x))) <= .Machine$double.eps)
[1] TRUE
> all(abs(1 - x / atan(tan(x))) <= .Machine$double.eps)
[1] TRUE
>