brob {Brobdingnag} | R Documentation |
Create, coerce to or test for a Brobdingnagian object
brob(x = double(), positive) as.brob(x) is.brob(x)
x |
Quantity to be tested, coerced in to Brobdingnagian form |
positive |
In function brob() , logical indicating whether
the number is positive (actually, positive or zero) |
Function as.brob()
is the user's workhorse: use this to coerce
numeric vectors to brob
s.
Function is.brob()
tests for its arguments being of class
brob
.
Function brob()
takes argument x
and returns a brob
formally equal to exp(x); set argument positive
to
FALSE
to return -exp(x). Thus calling function
exp(x)
simply returns brob(x)
. This function is not
really intended for the end user: it is confusing and includes no
argument checking. In general numerical work, use function
as.brob()
instead, although be aware that if you really really
want e^1e7, you should use brob(1e7)
;
this would be an exact representation.
Robin K. S, Hankin
googol <- as.brob(10)^100 googolplex <- 10^googol (googolplex/googol) / googolplex # Thus googolplex/googol == googolplex (!)