Rmpfr (version 0.8-2)

mpfr-distr-etc: Distribution Functions etc (MPFR)

Description

For some R standard (probability) density, distribution or quantile functions, we provide MPFR versions.

Usage

dpois (x, lambda, log = FALSE)
dbinom (x, size, prob, log = FALSE)
dnbinom(x, size, prob, mu, log = FALSE)
dnorm (x, mean = 0, sd = 1, log = FALSE)
dgamma(x, shape, rate = 1, scale = 1/rate, log = FALSE)
pnorm(q, mean = 0, sd = 1, lower.tail = TRUE, log.p = FALSE)

Arguments

x,q, lambda, size,prob, mu, mean,sd, shape,rate,scale

numeric or '>mpfr vectors. All of these are “recycled” to the length of the longest one. For their meaning/definition, see the corresponding standard R (stats package) function.

log, log.p, lower.tail

logical, see pnorm, dpois, etc.

Value

A vector of the same length as the longest of x,q, ..., of class '>mpfr with the high accuracy results of the corresponding standard R function.

Details

pnorm() is based on erf() and erfc() which have direct MPFR counter parts and are both reparametrizations of pnorm, erf(x) = 2*pnorm(sqrt(2)*x) and erfc(x) = 2* pnorm(sqrt(2)*x, lower=FALSE).

See Also

pnorm, dbinom, dnbinom, dgamma, dpois in standard package stats.

pbetaI(x, a,b) is a mpfr version of pbeta only for integer a and b.

Examples

# NOT RUN {
x <- 1400+ 0:10
print(dpois(x, 1000), digits =18) ## standard R's double precision
dpois(mpfr(x, 120), 1000)## more accuracy for the same
dpois(0:5, mpfr(10000, 80)) ## very small exponents

print(dbinom(0:8, 8, pr = 4 / 5), digits=18)
      dbinom(0:8, 8, pr = 4/mpfr(5, 99)) -> dB; dB

print(dnorm(     -5:5), digits=18)
      dnorm(mpfr(-5:5, prec=99))

## For pnorm() in the extreme tails, need an exponent range
## larger than the (MPFR and Rmpfr) default:
(old_eranges <- .mpfr_erange()) # typically -/+ 2^30
.mpfr_erange_set(value = (1-2^-52)*.mpfr_erange(c("min.emin","max.emax")))
tens <- mpfr(10^(4:7), 128)
pnorm(tens, lower.tail=FALSE, log.p=TRUE) # "works"
## reset to previous
.mpfr_erange_set( , old_eranges)
pnorm(tens, lower.tail=FALSE, log.p=TRUE) # all but first underflow to -Inf
# }