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factory

Create a function for applying a unary function to each element in an input array.

Installation

npm install @stdlib/math-array-tools-unary-factory

Alternatively,

• To load the package in a website via a script tag without installation and bundlers, use the ES Module available on the esm branch (see README).
• If you are using Deno, visit the deno branch (see README for usage intructions).
• For use in Observable, or in browser/node environments, use the Universal Module Definition (UMD) build available on the umd branch (see README).

The branches.md 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

var factory = require( '@stdlib/math-array-tools-unary-factory' );

factory( fcn, idtypes, odtypes, policy )

Returns a function for applying a unary function to each element in an input array.

var abs = require( '@stdlib/math-base-special-abs' );

var dtypes = [ 'float64', 'float32', 'generic' ];
var policy = 'same';

var unary = factory( abs, dtypes, dtypes, policy );

The function has the following parameters:

• fcn: unary function to apply.
• idtypes: list of supported input data types.
• odtypes: list of supported input data types.
• policy: output data type policy.

unary( x[, options] )

Applies a unary function to each element in a provided input array.

var abs = require( '@stdlib/math-base-special-abs' );

var dtypes = [ 'float64', 'float32', 'generic' ];
var policy = 'same';

var unary = factory( abs, dtypes, dtypes, policy );

var v = unary( [ -1.0, 2.0, -3.0, 4.0 ] );
// returns [ 1.0, 2.0, 3.0, 4.0 ]

The function has the following parameters:

• x: input array.
• options: function options.

The function accepts the following options:

• dtype: output array data type. Setting this option, overrides the output data type policy.

By default, the function returns an array having a data type determined by the output data type policy. To override the default behavior, set the dtype option.

var abs = require( '@stdlib/math-base-special-abs' );

var dtypes = [ 'float64', 'float32', 'generic' ];
var policy = 'same';

var unary = factory( abs, dtypes, dtypes, policy );

var v = unary( [ -1.0, 2.0, -3.0, 4.0 ], {
    'dtype': 'float64'
});
// returns <Float64Array>[ 1.0, 2.0, 3.0, 4.0 ]

unary.assign( x, out )

Applies a unary function to each element in a provided input array and assigns results to a provided output array.

var abs = require( '@stdlib/math-base-special-abs' );
var zeros = require( '@stdlib/array-zeros' );

var dtypes = [ 'float64', 'float32', 'generic' ];
var policy = 'same';

var unary = factory( abs, dtypes, dtypes, policy );

var out = zeros( 4, 'float64' );
// returns <Float64Array>[ 0.0, 0.0, 0.0, 0.0 ]

var v = unary.assign( [ -1.0, 2.0, -3.0, 4.0 ], out );
// returns <Float64Array>[ 1.0, 2.0, 3.0, 4.0 ]

var bool = ( v === out );
// returns true

The method has the following parameters:

• x: input array.
• out: output array.

Notes

• The output data type policy only applies to the function returned by factory. For the assign method, the output array is allowed to be any array-like object, including accessor arrays.

Examples

var base = require( '@stdlib/math-base-special-sin' );
var uniform = require( '@stdlib/random-array-uniform' );
var dtypes = require( '@stdlib/array-dtypes' );
var dtype = require( '@stdlib/array-dtype' );
var logEach = require( '@stdlib/console-log-each' );
var factory = require( '@stdlib/math-array-tools-unary-factory' );

// Define the supported input and output data types:
var idt = dtypes( 'real_and_generic' );
var odt = dtypes( 'real_floating_point_and_generic' );

// Define the policy mapping an input data type to an output data type:
var policy = 'real_floating_point_and_generic';

// Create an interface for computing the element-wise sine:
var sin = factory( base, idt, odt, policy );

// Generate an array of random numbers:
var x = uniform( 10, -1.0, 1.0, {
    'dtype': 'generic'
});

// Compute the element-wise sine:
var y = sin( x );

// Resolve the output array data type:
var dt = dtype( y );
console.log( dt );

// Print the results:
logEach( 'sin(%0.5f) = %0.5f', x, y );

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Notice

This package is part of 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, see the main project repository.

Community

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License

See LICENSE.

Copyright

Copyright © 2016-2025. The Stdlib Authors.