randu {datasets} | R Documentation |
400 triples of successive random numbers were taken from the VAX FORTRAN function RANDU running under VMS 1.5.
randu
A data frame with 400 observations on 3 variables named x
,
y
and z
which give the first, second and third random
number in the triple.
In three dimensional displays it is evident that the triples fall on 15 parallel planes in 3-space. This can be shown theoretically to be true for all triples from the RANDU generator.
These particular 400 triples start 5 apart in the sequence, that is they are ((U[5i+1], U[5i+2], U[5i+3]), i= 0, ..., 399), and they are rounded to 6 decimal places.
Under VMS versions 2.0 and higher, this problem has been fixed.
David Donoho
## Not run: ## We could re-generate the dataset by the following R code seed <- as.double(1) RANDU <- function() { seed <<- ((2^16 + 3) * seed) %% (2^31) seed/(2^31) } for(i in 1:400) { U <- c(RANDU(), RANDU(), RANDU(), RANDU(), RANDU()) print(round(U[1:3], 6)) } ## End(Not run)