Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/stdlib-js/random-strided-tools-unary-factory

Create a factory function for filling strided arrays with pseudorandom values drawn from a unary PRNG.
https://github.com/stdlib-js/random-strided-tools-unary-factory

factory fcn func function generator javascript math mathematics node node-js nodejs prng pseudorandom rand random rng statistics stats stdlib tools

Last synced: 4 months ago
JSON representation

Create a factory function for filling strided arrays with pseudorandom values drawn from a unary PRNG.

Awesome Lists containing this project

README 

        



  

    About stdlib...

  

  
We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.


  
The library is fully decomposable, being architected in such a way that you can swap out and mix and match APIs and functionality to cater to your exact preferences and use cases.


  
When you use stdlib, you can be absolutely certain that you are using the most thorough, rigorous, well-written, studied, documented, tested, measured, and high-quality code out there.


  
To join us in bringing numerical computing to the web, get started by checking us out on GitHub, and please consider financially supporting stdlib. We greatly appreciate your continued support!



# unaryFactory



[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url] 



> Create a factory function for filling strided arrays with pseudorandom values drawn from a unary PRNG.



## Installation



```bash

npm install @stdlib/random-strided-tools-unary-factory

```



Alternatively,



-   To load the package in a website via a `script` tag without installation and bundlers, use the [ES Module][es-module] available on the [`esm`][esm-url] branch (see [README][esm-readme]).

-   If you are using Deno, visit the [`deno`][deno-url] branch (see [README][deno-readme] for usage intructions).

-   For use in Observable, or in browser/node environments, use the [Universal Module Definition (UMD)][umd] build available on the [`umd`][umd-url] branch (see [README][umd-readme]).



The [branches.md][branches-url] file summarizes the available branches and displays a diagram illustrating their relationships.



To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.



## Usage



```javascript

var unaryFactory = require( '@stdlib/random-strided-tools-unary-factory' );

```



#### unaryFactory( prng )



Returns a factory function for filling strided arrays with pseudorandom values drawn from a unary PRNG.



```javascript

var exponential = require( '@stdlib/random-base-exponential' );



var factory = unaryFactory( exponential );

// returns 

```



The function has the following parameters:



-   **prng**: unary pseudorandom number generator.



* * *



#### factory( \[options] )



Returns a function for filling strided arrays with pseudorandom values drawn from a unary PRNG.



```javascript

var exponential = require( '@stdlib/random-base-exponential' );



var factory = unaryFactory( exponential );

// returns 



var random = factory();

// returns 

```



The function has the following parameters:



-   **options**: function options.



The function supports the following options:



-   **prng**: pseudorandom number generator which generates uniformly distributed pseudorandom numbers.

-   **seed**: pseudorandom value generator seed.

-   **state**: pseudorandom value generator state.

-   **copy**: boolean indicating whether to copy a provided pseudorandom value generator state.



To use a custom PRNG as the underlying source of uniformly distributed pseudorandom numbers, set the `prng` option.



```javascript

var Float64Array = require( '@stdlib/array-float64' );

var minstd = require( '@stdlib/random-base-minstd' );

var exponential = require( '@stdlib/random-base-exponential' );



var factory = unaryFactory( exponential );

// returns 



var opts = {

    'prng': minstd.normalized

};



var random = factory( opts );

// returns 



var out = new Float64Array( 10 );

random( out.length, [ 2.0 ], 0, out, 1 );

```



To seed the underlying pseudorandom number generator, set the `seed` option.



```javascript

var Float64Array = require( '@stdlib/array-float64' );

var exponential = require( '@stdlib/random-base-exponential' );



var factory = unaryFactory( exponential );

// returns 



var opts = {

    'seed': 12345

};



var random = factory( opts );

// returns 



var out = new Float64Array( 10 );

random( out.length, [ 2.0 ], 0, out, 1 );

```



* * *



#### random( N, param1, sp1, out, so )



Fills a strided array with pseudorandom values drawn from a unary PRNG.



```javascript

var Float64Array = require( '@stdlib/array-float64' );

var exponential = require( '@stdlib/random-base-exponential' );



var factory = unaryFactory( exponential );

// returns 



var random = factory();

// returns 



var out = new Float64Array( 10 );

// returns 



var v = random( out.length, [ 2.0 ], 0, out, 1 );

// returns 

```



The function has the following parameters:



-   **N**: number of indexed elements.

-   **param1**: PRNG parameter.

-   **sp1**: index increment for `param1`.

-   **out**: output array.

-   **so**: index increment for `out`.



The `N` and stride parameters determine which strided array elements are accessed at runtime. For example, to access every other value in `out`,



```javascript

var Float64Array = require( '@stdlib/array-float64' );

var exponential = require( '@stdlib/random-base-exponential' );



var factory = unaryFactory( exponential );

// returns 



var random = factory();

// returns 



var out = [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ];



random( 3, [ 2.0 ], 0, out, 2 );

```



Note that indexing is relative to the first index. To introduce an offset, use [`typed array`][mdn-typed-array] views.



```javascript

var Float64Array = require( '@stdlib/array-float64' );

var exponential = require( '@stdlib/random-base-exponential' );



var factory = unaryFactory( exponential );

// returns 



var random = factory();

// returns 



// Initial array:

var param0 = new Float64Array( [ 5.0, 5.0, 5.0, 5.0, 5.0, 5.0 ] );



// Create offset view:

var param1 = new Float64Array( param0.buffer, param0.BYTES_PER_ELEMENT*3 ); // start at 4th element



// Create an output array:

var out = new Float64Array( 3 );



// Fill the output array:

random( out.length, param1, -1, out, 1 );

```



#### random.ndarray( N, param1, sp1, op1, out, so, oo )



Fills a strided array with pseudorandom values drawn from a unary PRNG using alternative indexing semantics.



```javascript

var Float64Array = require( '@stdlib/array-float64' );

var exponential = require( '@stdlib/random-base-exponential' );



var factory = unaryFactory( exponential );

// returns 



var random = factory();

// returns 



var out = new Float64Array( 10 );

// returns 



var v = random.ndarray( out.length, [ 2.0 ], 0, 0, out, 1, 0 );

// returns 

```



The function has the following additional parameters:



-   **op1**: starting index for `param1`.

-   **oo**: starting index for `out`.



While [`typed array`][mdn-typed-array] views mandate a view offset based on the underlying `buffer`, the offset parameters support indexing semantics based on starting indices. For example, to access every other value in `out` starting from the second value,



```javascript

var exponential = require( '@stdlib/random-base-exponential' );



var factory = unaryFactory( exponential );

// returns 



var random = factory();

// returns 



var out = [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ];



random.ndarray( 3, [ 2.0 ], 0, 0, out, 2, 1 );

```



* * *



#### random.PRNG



The underlying pseudorandom number generator.



```javascript

var exponential = require( '@stdlib/random-base-exponential' );



var factory = unaryFactory( exponential );

// returns 



var random = factory();

// returns 



var prng = random.PRNG;

// returns 

```



#### random.seed



The value used to seed the underlying pseudorandom number generator.



```javascript

var exponential = require( '@stdlib/random-base-exponential' );



var factory = unaryFactory( exponential );

// returns 



var random = factory();

// returns 



var seed = random.seed;

// returns 

```



If the `factory` function is provided a PRNG for uniformly distributed numbers, the associated property value on the returned function is `null`.



```javascript

var minstd = require( '@stdlib/random-base-minstd-shuffle' ).normalized;

var exponential = require( '@stdlib/random-base-exponential' );



var factory = unaryFactory( exponential );

// returns 



var random = factory({

    'prng': minstd

});

// returns 



var seed = random.seed;

// returns null

```



#### random.seedLength



Length of underlying pseudorandom number generator seed.



```javascript

var exponential = require( '@stdlib/random-base-exponential' );



var factory = unaryFactory( exponential );

// returns 



var random = factory();

// returns 



var len = random.seedLength;

// returns 

```



If the `factory` function is provided a PRNG for uniformly distributed numbers, the associated property value on the returned function is `null`.



```javascript

var minstd = require( '@stdlib/random-base-minstd-shuffle' ).normalized;

var exponential = require( '@stdlib/random-base-exponential' );



var factory = unaryFactory( exponential );

// returns 



var random = factory({

    'prng': minstd

});

// returns 



var len = random.seedLength;

// returns null

```



#### random.state



Writable property for getting and setting the underlying pseudorandom number generator state.



```javascript

var exponential = require( '@stdlib/random-base-exponential' );



var factory = unaryFactory( exponential );

// returns 



var random = factory();

// returns 



var state = random.state;

// returns 

```



If the `factory` function is provided a PRNG for uniformly distributed numbers, the associated property value on the returned function is `null`.



```javascript

var minstd = require( '@stdlib/random-base-minstd-shuffle' ).normalized;

var exponential = require( '@stdlib/random-base-exponential' );



var factory = unaryFactory( exponential );

// returns 



var random = factory({

    'prng': minstd

});

// returns 



var state = random.state;

// returns null

```



#### random.stateLength



Length of underlying pseudorandom number generator state.



```javascript

var exponential = require( '@stdlib/random-base-exponential' );



var factory = unaryFactory( exponential );

// returns 



var random = factory();

// returns 



var len = random.stateLength;

// returns 

```



If the `factory` function is provided a PRNG for uniformly distributed numbers, the associated property value on the returned function is `null`.



```javascript

var minstd = require( '@stdlib/random-base-minstd-shuffle' ).normalized;

var exponential = require( '@stdlib/random-base-exponential' );



var factory = unaryFactory( exponential );

// returns 



var random = factory({

    'prng': minstd

});

// returns 



var len = random.stateLength;

// returns null

```



#### random.byteLength



Size (in bytes) of underlying pseudorandom number generator state.



```javascript

var exponential = require( '@stdlib/random-base-exponential' );



var factory = unaryFactory( exponential );

// returns 



var random = factory();

// returns 



var sz = random.byteLength;

// returns 

```



If the `factory` function is provided a PRNG for uniformly distributed numbers, the associated property value on the returned function is `null`.



```javascript

var minstd = require( '@stdlib/random-base-minstd-shuffle' ).normalized;

var exponential = require( '@stdlib/random-base-exponential' );



var factory = unaryFactory( exponential );

// returns 



var random = factory({

    'prng': minstd

});

// returns 



var sz = random.byteLength;

// returns null

```



* * *



## Examples



```javascript

var exponential = require( '@stdlib/random-base-exponential' );

var zeros = require( '@stdlib/array-zeros' );

var zeroTo = require( '@stdlib/array-zero-to' );

var logEach = require( '@stdlib/console-log-each' );

var unaryFactory = require( '@stdlib/random-strided-tools-unary-factory' );



// Create a PRNG factory function:

var factory = unaryFactory( exponential );

// returns 



// Specify a PRNG seed:

var opts = {

    'seed': 1234

};



// Create a function for filling strided arrays:

var rand1 = factory( opts );

// returns 



// Create an array:

var x1 = zeros( 10, 'float64' );



// Fill the array with pseudorandom numbers:

rand1( x1.length, [ 2.0 ], 0, x1, 1 );



// Create another function for filling strided arrays:

var rand2 = factory( opts );

// returns 



// Create a second array:

var x2 = zeros( 10, 'generic' );



// Fill the array with the same pseudorandom numbers:

rand2( x2.length, [ 2.0 ], 0, x2, 1 );



// Create a list of indices:

var idx = zeroTo( x1.length, 'generic' );



// Print the array contents:

logEach( 'x1[%d] = %.2f; x2[%d] = %.2f', idx, x1, idx, x2 );

```



* * *



## Notice



This package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.



For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].



#### Community



[![Chat][chat-image]][chat-url]



---



## License



See [LICENSE][stdlib-license].



## Copyright



Copyright © 2016-2024. The Stdlib [Authors][stdlib-authors].



[npm-image]: http://img.shields.io/npm/v/@stdlib/random-strided-tools-unary-factory.svg

[npm-url]: https://npmjs.org/package/@stdlib/random-strided-tools-unary-factory



[test-image]: https://github.com/stdlib-js/random-strided-tools-unary-factory/actions/workflows/test.yml/badge.svg?branch=main

[test-url]: https://github.com/stdlib-js/random-strided-tools-unary-factory/actions/workflows/test.yml?query=branch:main



[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/random-strided-tools-unary-factory/main.svg

[coverage-url]: https://codecov.io/github/stdlib-js/random-strided-tools-unary-factory?branch=main



[chat-image]: https://img.shields.io/gitter/room/stdlib-js/stdlib.svg

[chat-url]: https://app.gitter.im/#/room/#stdlib-js_stdlib:gitter.im



[stdlib]: https://github.com/stdlib-js/stdlib



[stdlib-authors]: https://github.com/stdlib-js/stdlib/graphs/contributors



[umd]: https://github.com/umdjs/umd

[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules



[deno-url]: https://github.com/stdlib-js/random-strided-tools-unary-factory/tree/deno

[deno-readme]: https://github.com/stdlib-js/random-strided-tools-unary-factory/blob/deno/README.md

[umd-url]: https://github.com/stdlib-js/random-strided-tools-unary-factory/tree/umd

[umd-readme]: https://github.com/stdlib-js/random-strided-tools-unary-factory/blob/umd/README.md

[esm-url]: https://github.com/stdlib-js/random-strided-tools-unary-factory/tree/esm

[esm-readme]: https://github.com/stdlib-js/random-strided-tools-unary-factory/blob/esm/README.md

[branches-url]: https://github.com/stdlib-js/random-strided-tools-unary-factory/blob/main/branches.md



[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/random-strided-tools-unary-factory/main/LICENSE



[mdn-typed-array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray