Lognormal {base} | R Documentation |
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.
dlnorm(x, meanlog = 0, sdlog = 1) plnorm(q, meanlog = 0, sdlog = 1) qlnorm(p, meanlog = 0, sdlog = 1) rlnorm(n, meanlog = 0, sdlog = 1)
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 |
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) = 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.
dnorm
for the normal distribution.
dlnorm(1) == dnorm(0) x <- rlnorm(1000) # not yet always : all(abs(x - qlnorm(plnorm(x))) < 1e4 * .Machine$double.eps * x)