rnorm_truncated: Random draw from a truncated normal distribution

In soundgen: Sound Synthesis and Acoustic Analysis

Random draw from a truncated normal distribution

Description

rnorm_truncated generates random numbers from a normal distribution using rnorm(), but forced to remain within the specified low/high bounds. All proposals outside the boundaries (exclusive) are discarded, and the sampling is repeated until there are enough values within the specified range. Fully vectorized. Note: "truncnorm::truncnorm" is much faster, but it only accepts static low/high boundaries. rnorm_truncated2 is a simplified version of rnorm_truncated, in which values outside the bounds are simply reset to the low/high bounds. The shape of the resulting distribution is no longer Gaussian, but this is obviously much faster. Unlike in rnorm_truncated, "low" and "high" should be scalars, not vectors (ie static boundaries).

Usage

rnorm_truncated(
  n = 1,
  mean = 0,
  sd = 1,
  low = NULL,
  high = NULL,
  roundToInteger = FALSE,
  invalidArgAction = "adjust"
)

rnorm_truncated2(
  n = 1,
  mean = 0,
  sd = 1,
  low = NULL,
  high = NULL,
  roundToInteger = FALSE,
  invalidArgAction = "adjust"
)

Arguments

n	the number of values to return
mean	the mean of the normal distribution from which values are generated (vector of length 1 or n)
sd	the standard deviation of the normal distribution from which values are generated (vector of length 1 or n)
low, high	exclusive lower and upper bounds ((vectors of length 1 or n))
roundToInteger	boolean vector of length 1 or n. If TRUE, the corresponding value is rounded to the nearest integer.

Value

A vector of length n.

Examples

soundgen:::rnorm_truncated(n = 3, mean = 10, sd = 5, low = 7, high = NULL,
  roundToInteger = c(TRUE, FALSE, FALSE))
soundgen:::rnorm_truncated(n = 9, mean = c(10, 50, 100), sd = c(5, 0, 20),
  roundToInteger = TRUE) # vectorized
# in case of conflicts between mean and bounds, either adjust the mean:
soundgen:::rnorm_truncated(n = 3, mean = 10, sd = .1,
  low = c(15, 0, 0), high = c(100, 100, 8), invalidArgAction = 'adjust')
#... or ignore the boundaries
soundgen:::rnorm_truncated(n = 3, mean = 10, sd = .1,
  low = c(15, 0, 0), high = c(100, 100, 8), invalidArgAction = 'ignore')

hist(soundgen:::rnorm_truncated2(n = 100, mean = 10, sd = 5, low = 7, high = NULL,
  roundToInteger = c(TRUE, FALSE, FALSE)))
hist(soundgen:::rnorm_truncated2(n = 100, mean = c(10, 50, 100), sd = c(5, 0, 20),
  roundToInteger = TRUE)) # vectorized
# in case of conflicts between mean and bounds, either sample at random
# between the boundaries...
hist(soundgen:::rnorm_truncated2(n = 100, mean = 10, sd = .1,
  low = 10, high = 15, invalidArgAction = 'adjust'))
#... or ignore the boundaries
hist(soundgen:::rnorm_truncated2(n = 100, mean = 10, sd = .1,
  low = 15, high = 100, invalidArgAction = 'ignore'))
soundgen:::rnorm_truncated2(n = 6, mean = c(0, 0, 0, 0, 0, 3),
  sd = .05, low = 0, high = 6)

soundgen documentation built on Sept. 20, 2026, 5:07 p.m.