fillBy

Fill an input ndarray according to a callback function.

Installation

npm install @stdlib/ndarray-base-fill-by

Usage

var fillBy = require( '@stdlib/ndarray-base-fill-by' );

fillBy( x, fcn[, thisArg] )

Fills an input ndarray according to a callback function.

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

function fcn() {
    return 10.0;
}

var x = array( [ [ [ 1.0, 2.0 ] ], [ [ 3.0, 4.0 ] ], [ [ 5.0, 6.0 ] ] ] );
// returns <ndarray>[ [ [ 1.0, 2.0 ] ], [ [ 3.0, 4.0 ] ], [ [ 5.0, 6.0 ] ] ]

var out = fillBy( x, fcn );
// returns <ndarray>[ [ [ 10.0, 10.0 ] ], [ [ 10.0, 10.0 ] ], [ [ 10.0, 10.0 ] ] ]

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

The function accepts the following arguments:

• x: array-like object containing an input ndarray.
• fcn: callback function.
• thisArg: callback function execution context (optional).

To set the callback function execution context, provide a thisArg.

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

function fcn( value ) {
    return value * 10.0;
}

var x = array( [ [ [ 1.0, 2.0 ] ], [ [ 3.0, 4.0 ] ], [ [ 5.0, 6.0 ] ] ] );
// returns <ndarray>[ [ [ 1.0, 2.0 ] ], [ [ 3.0, 4.0 ] ], [ [ 5.0, 6.0 ] ] ]

var ctx = {
    'factor': 10.0
};

var out = fillBy( x, fcn, ctx );
// returns <ndarray>[ [ [ 10.0, 20.0 ] ], [ [ 30.0, 40.0 ] ], [ [ 50.0, 60.0 ] ] ]

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

Notes

• A provided ndarray should be an object with the following properties:

  • dtype: data type.
  • data: data buffer.
  • shape: dimensions.
  • strides: stride lengths.
  • offset: index offset.
  • order: specifies whether an ndarray is row-major (C-style) or column major (Fortran-style).

• The callback function is provided the following arguments:

  • value: current array element.
  • indices: current array element indices.
  • arr: the input ndarray.

• The function mutates the input ndarray.

• The function assumes that each element in the underlying input ndarray data buffer has one, and only one, corresponding element in input ndarray view (i.e., a provided ndarray is not a broadcasted ndarray view).

Examples

var discreteUniform = require( '@stdlib/random-base-discrete-uniform' ).factory;
var ndarray2array = require( '@stdlib/ndarray-to-array' );
var zeros = require( '@stdlib/ndarray-zeros' );
var fillBy = require( '@stdlib/ndarray-base-fill-by' );

// Create a zero-filled ndarray:
var x = zeros( [ 5, 2 ], {
    'dtype': 'generic'
});
console.log( ndarray2array( x ) );

// Fill the ndarray with random values:
fillBy( x, discreteUniform( -100, 100 ) );
console.log( ndarray2array( x ) );

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

License

See LICENSE.

Copyright

Copyright © 2016-2026. The Stdlib Authors.