object_mode.js (2905B)
1 /** 2 * @license Apache-2.0 3 * 4 * Copyright (c) 2018 The Stdlib Authors. 5 * 6 * Licensed under the Apache License, Version 2.0 (the "License"); 7 * you may not use this file except in compliance with the License. 8 * You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 19 'use strict'; 20 21 // MODULES // 22 23 var isObject = require( '@stdlib/assert/is-plain-object' ); 24 var copy = require( '@stdlib/utils/copy' ); 25 var RandomStream = require( './main.js' ); 26 27 28 // MAIN // 29 30 /** 31 * Returns an "objectMode" readable stream for generating pseudorandom numbers drawn from a Laplace (double exponential) distribution. 32 * 33 * @param {number} mu - mean 34 * @param {PositiveNumber} b - scale parameter 35 * @param {Options} [options] - stream options 36 * @param {(string|null)} [options.encoding=null] - specifies how `Buffer` objects should be decoded to `strings` 37 * @param {NonNegativeNumber} [options.highWaterMark] - specifies the maximum number of objects to store in an internal buffer before ceasing to generate additional pseudorandom numbers 38 * @param {NonNegativeInteger} [options.iter] - number of iterations 39 * @param {PRNG} [options.prng] - pseudorandom number generator which generates uniformly distributed pseudorandom numbers 40 * @param {PRNGSeedMT19937} [options.seed] - pseudorandom number generator seed 41 * @param {PRNGStateMT19937} [options.state] - pseudorandom number generator state 42 * @param {boolean} [options.copy=true] - boolean indicating whether to copy a provided pseudorandom number generator state 43 * @param {PositiveInteger} [options.siter] - number of iterations after which to emit the PRNG state 44 * @throws {TypeError} `mu` must be a number 45 * @throws {TypeError} `b` must be a positive number 46 * @throws {TypeError} options argument must be an object 47 * @throws {TypeError} must provide valid options 48 * @throws {Error} must provide a valid state 49 * @returns {RandomStream} Stream instance 50 * 51 * @example 52 * var inspectStream = require( '@stdlib/streams/node/inspect-sink' ); 53 * 54 * function log( v ) { 55 * console.log( v ); 56 * } 57 * 58 * var opts = { 59 * 'iter': 10 60 * }; 61 * 62 * var stream = objectMode( 2.0, 1.0, opts ); 63 * 64 * stream.pipe( inspectStream.objectMode( log ) ); 65 */ 66 function objectMode( mu, b, options ) { 67 var opts; 68 if ( arguments.length > 2 ) { 69 opts = options; 70 if ( !isObject( opts ) ) { 71 throw new TypeError( 'invalid argument. Options must be an object. Value: `' + opts + '`.' ); 72 } 73 opts = copy( options, 1 ); 74 } else { 75 opts = {}; 76 } 77 opts.objectMode = true; 78 return new RandomStream( mu, b, opts ); 79 } 80 81 82 // EXPORTS // 83 84 module.exports = objectMode;