{{alias}}( r, p ) Returns a pseudorandom number drawn from a negative binomial distribution. If `p` is not in the interval `(0,1)`, the function returns `NaN`. If `r` or `p` is `NaN`, the function returns `NaN`. Parameters ---------- r: number Number of successes until experiment is stopped. p: number Success probability. Returns ------- r: integer Pseudorandom number. Examples -------- > var r = {{alias}}( 20, 0.8 ); {{alias}}.factory( [r, p, ][options] ) Returns a pseudorandom number generator (PRNG) for generating pseudorandom numbers drawn from a negative binomial distribution. If provided `r` and `p`, the returned PRNG returns random variates drawn from the specified distribution. If not provided `r` and `p`, the returned PRNG requires that both `r` and `p` be provided at each invocation. Parameters ---------- r: number (optional) Number of successes until experiment is stopped. p: number (optional) Success probability. options: Object (optional) Options. options.prng: Function (optional) Pseudorandom number generator (PRNG) for generating uniformly distributed pseudorandom numbers on the interval `[0,1)`. If provided, the `state` and `seed` options are ignored. In order to seed the returned pseudorandom number generator, one must seed the provided `prng` (assuming the provided `prng` is seedable). options.seed: integer|ArrayLikeObject (optional) Pseudorandom number generator seed. The seed may be either a positive unsigned 32-bit integer or, for arbitrary length seeds, an array-like object containing unsigned 32-bit integers. options.state: Uint32Array (optional) Pseudorandom number generator state. If provided, the `seed` option is ignored. options.copy: boolean (optional) Boolean indicating whether to copy a provided pseudorandom number generator state. Setting this option to `false` allows sharing state between two or more pseudorandom number generators. Setting this option to `true` ensures that a returned generator has exclusive control over its internal state. Default: true. Returns ------- rand: Function Pseudorandom number generator (PRNG). Examples -------- // Basic usage: > var rand = {{alias}}.factory(); > var r = rand( 20, 0.3 ); > r = rand( 10, 0.77 ); // Provide `r` and `p`: > rand = {{alias}}.factory( 10, 0.8 ); > r = rand(); > r = rand(); {{alias}}.NAME Generator name. Examples -------- > var str = {{alias}}.NAME 'negative-binomial' {{alias}}.PRNG Underlying pseudorandom number generator. Examples -------- > var prng = {{alias}}.PRNG; {{alias}}.seed Pseudorandom number generator seed. Examples -------- > var seed = {{alias}}.seed; {{alias}}.seedLength Length of generator seed. Examples -------- > var len = {{alias}}.seedLength; {{alias}}.state Generator state. Examples -------- > var r = {{alias}}( 20, 0.3 ) > r = {{alias}}( 20, 0.3 ) > r = {{alias}}( 20, 0.3 ) // Get a copy of the current state: > var state = {{alias}}.state > r = {{alias}}( 20, 0.3 ) > r = {{alias}}( 20, 0.3 ) // Set the state: > {{alias}}.state = state; // Replay the last two pseudorandom numbers: > r = {{alias}}( 20, 0.3 ) > r = {{alias}}( 20, 0.3 ) {{alias}}.stateLength Length of generator state. Examples -------- > var len = {{alias}}.stateLength; {{alias}}.byteLength Size (in bytes) of generator state. Examples -------- > var sz = {{alias}}.byteLength; {{alias}}.toJSON() Serializes the pseudorandom number generator as a JSON object. Returns ------- out: Object JSON representation. Examples -------- > var o = {{alias}}.toJSON() { 'type': 'PRNG', 'name': '...', 'state': {...}, 'params': [] } See Also --------