18.1 Lognormal distribution
18.1.1 Probability density function
If \(\mu \in \mathbb{R}\) and \(\sigma \in \mathbb{R}^+\), then for \(y \in \mathbb{R}^+\), \[ \text{LogNormal}(y|\mu,\sigma) = \frac{1}{\sqrt{2 \pi} \ \sigma} \, \frac{1}{y} \ \exp \! \left( - \, \frac{1}{2} \, \left( \frac{\log y - \mu}{\sigma} \right)^2 \right) . \]
18.1.2 Sampling statement
y ~ lognormal(mu, sigma)
Increment target log probability density with lognormal_lupdf(y | mu, sigma).
Available since 2.0
18.1.3 Stan functions
real lognormal_lpdf(reals y | reals mu, reals sigma)
The log of the lognormal density of y given location mu and scale
sigma
Available since 2.12
real lognormal_lupdf(reals y | reals mu, reals sigma)
The log of the lognormal density of y given location mu and scale
sigma dropping constant additive terms
Available since 2.25
real lognormal_cdf(reals y, reals mu, reals sigma)
The cumulative lognormal distribution function of y given location mu
and scale sigma
Available since 2.0
real lognormal_lcdf(reals y | reals mu, reals sigma)
The log of the lognormal cumulative distribution function of y given
location mu and scale sigma
Available since 2.12
real lognormal_lccdf(reals y | reals mu, reals sigma)
The log of the lognormal complementary cumulative distribution
function of y given location mu and scale sigma
Available since 2.12
R lognormal_rng(reals mu, reals sigma)
Generate a lognormal variate with location mu and scale sigma; may
only be used in transformed data and generated quantities blocks.
For a description of argument and return types, see section
vectorized PRNG functions.
Available since 2.22