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    @stdlib/utils-map3d
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    0.0.1 • Public • Published

    map3d

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    Apply a function to each nested element in a three-dimensional nested array and assign the result to a nested element in a new three-dimensional nested array.

    Installation

    npm install @stdlib/utils-map3d

    Usage

    var map3d = require( '@stdlib/utils-map3d' );

    map3d( arr, fcn[, thisArg] )

    Applies a function to each nested element in a three-dimensional nested array and assigns the result to a nested element in a new three-dimensional nested array.

    var naryFunction = require( '@stdlib/utils-nary-function' );
    var abs = require( '@stdlib/math-base-special-abs' );
    
    var arr = [
        [ [ -1, -2, -3 ] ],
        [ [ -4, -5, -6 ] ]
    ];
    
    var out = map3d( arr, naryFunction( abs, 1 ) );
    // returns [ [ [ 1, 2, 3 ] ], [ [ 4, 5, 6 ] ] ]

    The applied function is provided the following arguments:

    • value: array element.
    • i: index of the first dimension.
    • j: index of the second dimension.
    • k: index of the third dimension.
    • arr: input array.

    To set the this context when invoking the input function, provide a thisArg.

    var abs = require( '@stdlib/math-base-special-abs' );
    
    function fcn( v ) {
        this.count += 1;
        return abs( v );
    }
    
    var arr = [
        [ [ -1, -2, -3 ] ],
        [ [ -4, -5, -6 ] ]
    ];
    
    var ctx = {
        'count': 0
    };
    
    var out = map3d( arr, fcn, ctx );
    // returns [ [ [ 1, 2, 3 ] ], [ [ 4, 5, 6 ] ] ]
    
    var cnt = ctx.count;
    // returns 6

    Examples

    var filledarrayBy = require( '@stdlib/array-filled-by' );
    var discreteUniform = require( '@stdlib/random-base-discrete-uniform' ).factory;
    var naryFunction = require( '@stdlib/utils-nary-function' );
    var abs2 = require( '@stdlib/math-base-special-abs2' );
    var map3d = require( '@stdlib/utils-map3d' );
    
    function nestedFill( i ) {
        var rand = discreteUniform( -10*(i+1), 10*(i+1) );
        return filledarrayBy( 10, 'float64', rand );
    }
    
    function fill() {
        return filledarrayBy( 10, 'generic', nestedFill );
    }
    
    // Create a three-dimensional nested array:
    var x = filledarrayBy( 10, 'generic', fill );
    
    // Create an explicit unary function:
    var f = naryFunction( abs2, 1 );
    
    // Compute the element-wise squared absolute value...
    var y = map3d( x, f );
    
    console.log( 'x:' );
    console.log( x );
    
    console.log( 'y:' );
    console.log( y );

    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.

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    License

    See LICENSE.

    Copyright

    Copyright © 2016-2022. The Stdlib Authors.

    Install

    npm i @stdlib/utils-map3d

    Homepage

    stdlib.io

    DownloadsWeekly Downloads

    24

    Version

    0.0.1

    License

    Apache-2.0

    Unpacked Size

    43.1 kB

    Total Files

    9

    Last publish

    Collaborators

    • stdlib-bot
    • kgryte
    • planeshifter
    • rreusser