dtnorm: Truncated Normal Density Function

In dRiftDM: Estimating (Time-Dependent) Drift Diffusion Models

Truncated Normal Density Function

Description

Computes the probability density function for the truncated normal distribution. This version supports both vector and matrix input for x.

Usage

dtnorm(x, mean = 0, sd = 1, lower = -Inf, upper = Inf, log = FALSE)

rtnorm(n, mean = 0, sd = 1, lower = -Inf, upper = Inf)

Arguments

x	A numeric vector or matrix of values where the density should be evaluated.
mean	Mean of the normal distribution. Can be a scalar or vector (recycled if necessary).
sd	Standard deviation of the normal distribution. Can be a scalar or vector (recycled if necessary).
lower	Lower truncation bound. Can be a scalar or vector (recycled if necessary). Default is -Inf.
upper	Upper truncation bound. Can be a scalar or vector (recycled if necessary). Default is Inf.
log	Logical; if TRUE, probabilities p are given as log(p). Default is FALSE.

Details

The function evaluates the normal density at x and scales it to reflect truncation to the interval (lower, upper). Values outside the truncation bounds are assigned a density of 0 (or -Inf on the log scale). Internally, stats::dnorm and stats::pnorm are used.

If x is a matrix, the result retains the same dimensions. All other arguments are recycled as needed. For example, if x has two rows and 5 columns, then mean might provide 2 values, so that the first/second row is evaluated under the first/second mean value.

Value

A numeric vector or matrix of the same shape as x, containing the (possibly log) densities.

dRiftDM documentation built on Dec. 1, 2025, 5:08 p.m.