TITLE(Lognormal @@ The Log Normal Distribution)
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)
)
ALIAS(dlnorm)
ALIAS(plnorm)
ALIAS(qlnorm)
ALIAS(rlnorm)
DESCRIPTION(
These functions provide information about the log normal distribution
whose logarithm has mean equal to LANG(meanlog) and standard deviation
equal to LANG(sdlog).  LANG(dlnorm) gives the density, LANG(plnorm)
gives the distribution function LANG(qlnorm) gives the quantile
function and LANG(rlnorm) generates random deviates.
PARA
If LANG(meanlog) or LANG(sdlog) are not specified they assume the
default values of LANG(0) and LANG(1) respectively.
PARA
The log normal distribution has density
DEQN(
f(x) =
OVER(1 @@ SQRT(2 greekpi) greeksigma x)
SUP(e @@ DISPLAYSTYLE(
- SUP((LOG x - greekmu)@@2) / 2 SUP(greeksigma@@2)))
@@
f(x) = 1/(sqrt(2 pi) sigma x)
           e^-((log x - mu)^2 / (2 sigma^2))
)
where EQN(greekmu) and EQN(greeksigma) are the mean
and standard deviation of the logarithm.
)
SEEALSO(
LANG(LINK(dnorm)), etc.
)





