/**
* @license Apache-2.0
*
* Copyright (c) 2018 The Stdlib Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*    http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

'use strict';

// MODULES //

var knuth = require( './knuth.js' );
var rejection = require( './rejection.js' );


// MAIN //

/**
* Returns a pseudorandom number drawn from a Poisson distribution with parameter `lambda`.
*
* @private
* @param {PRNG} rand - PRNG for generating uniformly distributed numbers
* @param {PositiveNumber} lambda - mean
* @returns {NonNegativeInteger} pseudorandom number
*/
function poisson( rand, lambda ) {
	if ( lambda < 30.0 ) {
		return knuth( rand, lambda );
	}
	return rejection( rand, lambda );
}


// EXPORTS //

module.exports = poisson;