README.md

factory

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

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 );