| Lognormal {base} | R Documentation |
The Log Normal Distribution
Description
These functions provide information about the log normal distribution
whose logarithm has mean equal to meanlog and standard
deviation equal to sdlog. dlnorm gives the density,
plnorm gives the distribution function qlnorm gives the
quantile function and rlnorm generates random deviates.
If meanlog or sdlog are not specified they assume the
default values of 0 and 1 respectively.
The log normal distribution has density
f(x) = \frac{1}{\sqrt{2\pi}\sigma x} e^{-(\log(x) - \mu)^2/2 \sigma^2}%
where \mu and \sigma are the mean and standard
deviation of the logarithm.
Usage
dlnorm(x, meanlog = 0, sdlog = 1)
plnorm(q, meanlog = 0, sdlog = 1)
qlnorm(p, meanlog = 0, sdlog = 1)
rlnorm(n, meanlog = 0, sdlog = 1)
Arguments
x, q |
vector of quantiles. |
p |
vector of probabilities. |
n |
number of observations to generate. |
meanlog, sdlog |
mean and standard deviation of the distribution on the log scale |
See Also
dnorm for the normal distribution.
Examples
dlnorm(1) == dnorm(0)
x <- rlnorm(1000) # not yet always :
all(abs(x - qlnorm(plnorm(x))) < 1e4 * .Machine$double.eps * x)