@stdlib/utils-map3d
v0.2.2
Published
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.
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map3d
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.
- indices: current array element indices.
- 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 );
See Also
@stdlib/utils-map
: apply a function to each element in an array and assign the result to an element in an output array.@stdlib/utils-map2d
: apply a function to each nested element in an array of arrays and assign the result to a nested element in a new array of arrays.@stdlib/utils-map4d
: apply a function to each nested element in a four-dimensional nested array and assign the result to a nested element in a new four-dimensional nested array.@stdlib/utils-map5d
: apply a function to each nested element in a five-dimensional nested array and assign the result to a nested element in a new five-dimensional nested array.
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 © 2016-2024. The Stdlib Authors.