Function Reference: logninv

statistics: x = logninv (p)
statistics: x = logninv (p, mu)
statistics: x = logninv (p, mu, sigma)

Inverse of the log-normal cumulative distribution function (iCDF).

For each element of p, compute the quantile (the inverse of the CDF) of the log-normal distribution with mean mu and standard deviation sigma corresponding to the associated normal distribution. The size of x is the common size of p, mu, and sigma. A scalar input functions as a constant matrix of the same size as the other inputs.

If a random variable follows this distribution, its logarithm is normally distributed with mean mu and standard deviation sigma.

Default parameter values are mu = 0 and sigma = 1. Both parameters must be reals and sigma > 0. For sigma <= 0, NaN is returned.

Further information about the log-normal distribution can be found at https://en.wikipedia.org/wiki/Log-normal_distribution

See also: logncdf, lognpdf, lognrnd, lognfit, lognlike, lognstat

Source Code: logninv

Example: 1

 

 ## Plot various iCDFs from the log-normal distribution
 p = 0.001:0.001:0.999;
 x1 = logninv (p, 0, 1);
 x2 = logninv (p, 0, 0.5);
 x3 = logninv (p, 0, 0.25);
 plot (p, x1, "-b", p, x2, "-g", p, x3, "-r")
 grid on
 ylim ([0, 3])
 legend ({"μ = 0, σ = 1", "μ = 0, σ = 0.5", "μ = 0, σ = 0.25"}, ...
         "location", "northwest")
 title ("Log-normal iCDF")
 xlabel ("probability")
 ylabel ("values in x")

                    
plotted figure