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. > ##-*- 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 >