NewExponentialDistribution creates an ExponentialDistribution with the given mean.

NewPoissonDistribution creates a new new PoissonDistribution with the given average rate.

NewPoissonDistributionWithRand creates a new PoissonDistribution with the given average rate and random number generator.

Round computes the nearest integer to f, rounding ties towards positive infinity.

Sign returns -1 if f is negative, +1 if f is positive, and 0 if f is positive or negative zero or NaN.

SignInt64 returns -1 if f is negative, +1 if f is positive, and 0 if f is 0.

PoissonDistribution models the number of times an event occurs in an interval of time.

ExponentialDistribution represents an exponential distribution with a given mean.