logNormalNoise

logNormalNoise (m,s)

The logNormalNoise function returns a pseudo-random value from the lognormal distribution function whose probability distribution function is

$$\displaystyle f(x, m, s)=\frac{1}{x s \sqrt{2 \pi}} \exp \left\{-\frac{[\ln (x)-m]^{2}}{2 s^{2}}\right\},$$

with a mean

$$\displaystyle \exp \left(m+\frac{1}{2} s^{2}\right),$$

and variance

$$\displaystyle \exp \left(2 m+s^{2}\right)\left[\exp \left(s^{2}\right)-1\right] .$$

The random number generator initializes using the system clock when Igor Pro starts. This almost guarantees that you will never repeat a sequence. For repeatable "random" numbers, use SetRandomSeed. The algorithm uses the Mersenne Twister random number generator.

See Also

SetRandomSeed, Noise Functions, Statistical Analysis