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 GNU Scientific Library Reference Manual - Third Edition (v1.12) by M. Galassi, J. Davies, J. Theiler, B. Gough, G. Jungman, P. Alken, M. Booth, F. RossiPaperback (6"x9"), 592 pages, 60 figuresISBN 0954612078RRP £24.95 (\$39.95)

## 19.16 The Lognormal Distribution

Function: double gsl_ran_lognormal (const gsl_rng * r, double zeta, double sigma)
This function returns a random variate from the lognormal distribution. The distribution function is,
p(x) dx = {1 \over x \sqrt{2 \pi \sigma^2} } \exp(-(\ln(x) - \zeta)^2/2 \sigma^2) dx


for x > 0.

Function: double gsl_ran_lognormal_pdf (double x, double zeta, double sigma)
This function computes the probability density p(x) at x for a lognormal distribution with parameters zeta and sigma, using the formula given above.

Function: double gsl_cdf_lognormal_P (double x, double zeta, double sigma)
Function: double gsl_cdf_lognormal_Q (double x, double zeta, double sigma)
Function: double gsl_cdf_lognormal_Pinv (double P, double zeta, double sigma)
Function: double gsl_cdf_lognormal_Qinv (double Q, double zeta, double sigma)
These functions compute the cumulative distribution functions P(x), Q(x) and their inverses for the lognormal distribution with parameters zeta and sigma.
 ISBN 0954612078 GNU Scientific Library Reference Manual - Third Edition (v1.12) See the print edition