@stdlib/array/base/map2d/lib/assign.js

Arrays.

/**
* @license Apache-2.0
*
* Copyright (c) 2023 The Stdlib Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*    http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

'use strict';

// MAIN //

/**
* Applies a function to elements in a two-dimensional nested input array and assigns results to elements in a two-dimensional nested output array.
*
* ## Notes
*
* -   The function assumes that the input and output arrays have the same shape.
*
* @param {ArrayLikeObject<Collection>} x - input nested array
* @param {ArrayLikeObject<Collection>} y - output nested array
* @param {NonNegativeIntegerArray} shape - array shape
* @param {Function} fcn - function to apply
* @param {*} [thisArg] - function execution context
* @returns {Array<Array>} output array
*
* @example
* var ones2d = require( '@stdlib/array/base/ones2d' );
* var zeros2d = require( '@stdlib/array/base/zeros2d' );
*
* function scale( x ) {
*     return x * 10.0;
* }
*
* var shape = [ 2, 2 ];
*
* var x = ones2d( shape );
* var y = zeros2d( shape );
*
* var out = map2d( x, y, shape, scale );
* // returns [ [ 10.0, 10.0 ], [ 10.0, 10.0 ] ]
*
* var bool = ( out === y );
* // returns true
*/
function map2d( x, y, shape, fcn, thisArg ) {
	var S0;
	var S1;
	var i0;
	var i1;
	var x0;
	var y0;

	S0 = shape[ 1 ];
	S1 = shape[ 0 ];
	if ( S0 <= 0 || S1 <= 0 ) {
		return y;
	}
	for ( i1 = 0; i1 < S1; i1++ ) {
		x0 = x[ i1 ];
		y0 = y[ i1 ];
		for ( i0 = 0; i0 < S0; i0++ ) {
			y0[ i0 ] = fcn.call( thisArg, x0[ i0 ], [ i1, i0 ], x );
		}
	}
	return y;
}


// EXPORTS //

module.exports = map2d;