Lognormal Distribution - 5.2 English - 68552

AOCL API Guide (68552)

Document ID
68552
Release Date
2025-12-29
Version
5.2 English

Generates a vector of random variates from a lognormal distribution with probability density function, \(f (X)\), where:

\[f(X) = \frac{e^{-\frac{(\log X - \mu)^2}{2\sigma^2}}}{X \sigma \sqrt{2\pi}}\]

if X > 0, otherwise \(f (X) = 0\). Here μ is the mean, (XMU ) and \(\sigma 2\) the variance, (VAR) of the underlying Gaussian distribution.

C Generate 100 values from the Lognormal distribution
    INTEGER LSTATE,N
    PARAMETER (LSTATE=16,N=100)
    INTEGER I,INFO,SEED(1),STATE(LSTATE)
    DOUBLE PRECISION XMU,VAR
    DOUBLE PRECISION X(N)

C Set the seed
    SEED(1) = 1234

C Read in the distributional parameters
    READ(5,*) XMU,VAR

C Initialize the STATE vector
    CALL DRANDINITIALIZE(1,1,SEED,1,STATE,LSTATE,INFO)

C Generate N variates from the Lognormal distribution
    CALL DRANDLOGNORMAL(N,XMU,VAR,STATE,X,INFO)

C Print the results
    WRITE(6,*) (X(I),I=1,N)