RtoDPQ

0th

Percentile

Default procedure to fill slots d,p,q given r for a.c. distributions

function to do get empirical density, cumulative distribution and quantile function from random numbers

Keywords
distribution, arith, math
Usage
RtoDPQ(r, e = getdistrOption("RtoDPQ.e"), n = getdistrOption("DefaultNrGridPoints"))
Arguments
r
the random number generator
e
$10^e$ numbers are generated, a higher number leads to a better result.
n
The number of grid points used to create the approximated functions, a higher number leads to a better result.
Details

RtoDPQ generates $10^e$ random numbers, by default $$e = RtoDPQ.e$$. The density is formed on the basis of $n$ points using approxfun and density, by default $$n = DefaultNrGridPoints$$. The cumulative distribution function and the quantile function are also created on the basis of $n$ points using approxfun and ecdf. Of course, the results are usually not exact as they rely on random numbers.

Value

  • RtoDPQ returns a list of functions.
  • dfundensity
  • pfuncumulative distribution function
  • qfunquantile function

Note

Use RtoDPQ for absolutely continuous and RtoDPQ.d for discrete distributions.

concept

  • random sample
  • image distribution
  • absolutely continuous distribution
  • utility

See Also

UnivariateDistribution-class, density, approxfun, ecdf

Aliases
  • RtoDPQ
Examples
rn2 <- function(n){rnorm(n)^2}
x <- RtoDPQ(r = rn2, e = 4, n = 512)
# returns density, cumulative distribution and quantile function of
# squared standard normal distribution
x$dfun(4)
RtoDPQ(r = rn2, e = 5, n = 1024) # for a better result

rp2 <- function(n){rpois(n, lambda = 1)^2}
x <- RtoDPQ.d(r = rp2, e = 5)
# returns density, cumulative distribution and quantile function of
# squared Poisson distribution with parameter lambda=1
Documentation reproduced from package distr, version 2.0.2, License: LGPL-3

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