randnorm: Sample from a Univariate Normal or Lognormal Distribution

In ecosim: Toolbox for Aquatic Ecosystem Modeling

Description

Samples from a univariate Normal or Lognormal distribution with parameters valid in the original units. Just invokes a parameter transformation and calls rnorm as users often prefer to specify uncertainty in their original units rather than on the log scale as it is done in rlnorm.

Usage

randnorm(mean=0,sd=1,log=FALSE,n=1)

Arguments

mean	Mean of the random variable.
sd	Standard deviation of the random variable.
log	Indicator whether the log of the variable should be normally distributed (log=TRUE) rather than the variable itself. (Note: mean and sd are interpreted in original units also for log=TRUE.)
n	Sample size.

Author(s)

Peter Reichert <[e-mail]>

See Also

rnorm, rlnorm, randou.

Examples

n <- 10000

samp <- randnorm(mean=0,sd=1,n=n)
plot(1:length(samp),samp,xlab="index",ylab="y",cex=0.2)
mean(samp)
sd(samp)

samp <- randnorm(mean=2,sd=2,log=TRUE,n=n)
plot(1:length(samp),samp,ylim=c(0,25),xlab="index",ylab="y",cex=0.2)
mean(samp)
sd(samp)

ecosim documentation built on May 30, 2017, 4:45 a.m.