177 lines
3.9 KiB
Plaintext
177 lines
3.9 KiB
Plaintext
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{{alias}}( λ )
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Returns a pseudorandom number drawn from an exponential distribution.
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If `λ <= 0` or `λ` is `NaN`, the function returns `NaN`.
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Parameters
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----------
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λ: number
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Rate parameter.
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Returns
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-------
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r: number
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Pseudorandom number.
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Examples
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--------
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> var r = {{alias}}( 7.9 );
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{{alias}}.factory( [λ, ][options] )
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Returns a pseudorandom number generator (PRNG) for generating pseudorandom
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numbers drawn from an exponential distribution.
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If provided `λ`, the returned PRNG returns random variates drawn from the
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specified distribution.
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If not provided `λ`, the returned PRNG requires that `λ` be provided at each
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invocation.
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Parameters
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----------
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λ: number (optional)
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Rate parameter.
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options: Object (optional)
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Options.
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options.prng: Function (optional)
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Pseudorandom number generator (PRNG) for generating uniformly
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distributed pseudorandom numbers on the interval `[0,1)`. If provided,
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the `state` and `seed` options are ignored. In order to seed the
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returned pseudorandom number generator, one must seed the provided
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`prng` (assuming the provided `prng` is seedable).
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options.seed: integer|ArrayLikeObject<integer> (optional)
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Pseudorandom number generator seed. The seed may be either a positive
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unsigned 32-bit integer or, for arbitrary length seeds, an array-like
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object containing unsigned 32-bit integers.
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options.state: Uint32Array (optional)
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Pseudorandom number generator state. If provided, the `seed` option is
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ignored.
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options.copy: boolean (optional)
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Boolean indicating whether to copy a provided pseudorandom number
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generator state. Setting this option to `false` allows sharing state
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between two or more pseudorandom number generators. Setting this option
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to `true` ensures that a returned generator has exclusive control over
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its internal state. Default: true.
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Returns
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-------
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rand: Function
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Pseudorandom number generator (PRNG).
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Examples
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--------
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// Basic usage:
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> var rand = {{alias}}.factory();
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> var r = rand( 5.0 );
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> r = rand( 3.14 );
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// Provide `λ`:
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> rand = {{alias}}.factory( 10.0 );
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> r = rand();
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> r = rand();
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{{alias}}.NAME
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Generator name.
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Examples
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--------
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> var str = {{alias}}.NAME
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'exponential'
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{{alias}}.PRNG
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Underlying pseudorandom number generator.
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Examples
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--------
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> var prng = {{alias}}.PRNG;
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{{alias}}.seed
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Pseudorandom number generator seed.
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Examples
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--------
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> var seed = {{alias}}.seed;
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{{alias}}.seedLength
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Length of generator seed.
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Examples
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--------
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> var len = {{alias}}.seedLength;
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{{alias}}.state
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Generator state.
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Examples
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--------
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> var r = {{alias}}( 7.9 )
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<number>
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> r = {{alias}}( 7.9 )
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<number>
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> r = {{alias}}( 7.9 )
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<number>
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// Get a copy of the current state:
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> var state = {{alias}}.state
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<Uint32Array>
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> r = {{alias}}( 7.9 )
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<number>
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> r = {{alias}}( 7.9 )
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<number>
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// Set the state:
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> {{alias}}.state = state;
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// Replay the last two pseudorandom numbers:
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> r = {{alias}}( 7.9 )
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<number>
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> r = {{alias}}( 7.9 )
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<number>
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{{alias}}.stateLength
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Length of generator state.
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Examples
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--------
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> var len = {{alias}}.stateLength;
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{{alias}}.byteLength
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Size (in bytes) of generator state.
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Examples
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--------
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> var sz = {{alias}}.byteLength;
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{{alias}}.toJSON()
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Serializes the pseudorandom number generator as a JSON object.
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Returns
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-------
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out: Object
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JSON representation.
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Examples
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--------
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> var o = {{alias}}.toJSON()
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{ 'type': 'PRNG', 'name': '...', 'state': {...}, 'params': [] }
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See Also
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--------
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