binomialNoise

binomialNoise (n, p)

The binomialNoise function returns a pseudo-random value from the binomial distribution

$$\displaystyle f(x)=\binom{n}{x} p^{x}(1-p)^{n-x}, \quad \begin{array}{c} 0 \leq p \leq 1 \\ x=0,1,2 \ldots n \end{array}$$

whose mean is np and variance is

$$\displaystyle n p(1-p) .$$

When n is large such that pⁿ is zero to machine accuracy the function returns NaN. Note that when n is large such that np(1-p) > 5 and 0.1 < p < 0.9 you can replace the binomial variate with a normal variate with mean np and standard deviation sqrt(n*p*(1-p)).

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

See Also

SetRandomSeed, Noise Functions, Statistical Analysis