# dtrunc: Probability density function of truncated random variables In CharlotteJana/momcalc: Symbolic Moment Calculation

## Description

This function computes values for the probability density function of a truncated random variable. It was originally implemented in package truncdist and slightly modified to return zeros in case that the trunction interval [a, b] is not inside the support of the density function.

## Usage

 `1` ```dtrunc(x, spec, a = -Inf, b = Inf, ...) ```

## Arguments

 `x` A numeric vector of quantile values `spec` a character value that specifies the underlying probability distribution `a` a numeric value for the lower bound of the random variable `b` a numeric value for the upper bound of the random variable `...` other arguments are passed to the corresponding quantile function

## Details

The `R` function is used to access the required probability density and cumulative distribution functions of the underlying unrestricted random variable.

## Value

A vector of density function values.

## References

Nadarajah, S. and S. Kotz, 2006. `R` Programs for Computing Truncated Distributions, Journal of Statistical Software, 16, August 2006, http://www.jstatsoft.org/v16/c02

## Examples

 ```1 2 3 4 5 6 7 8 9``` ```x <- seq(0, 3, 0.1) dtrunc(x, spec = "norm", a = 1, b = 2) curve(dtrunc(x, spec = "norm", a = -Inf, b = 1), -10, 2) ## Not run: # different results for intervals outside the support of the density function: truncdist::dtrunc(x, spec = "norm", a = 20, b = 30) # gives error momcalc::dtrunc(x, spec = "norm", a = 20, b = 30) # gives only a warning ## End(Not run) ```

CharlotteJana/momcalc documentation built on Oct. 17, 2019, 7:21 a.m.