All files / dcartesian-product/lib ndarray.js

62.61% Statements 67/107
100% Branches 1/1
0% Functions 0/1
62.61% Lines 67/107

Press n or j to go to the next uncovered block, b, p or k for the previous block.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 1081x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x                                                                                 1x 1x 1x 1x 1x  
/**
* @license Apache-2.0
*
* Copyright (c) 2026 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.
*/
 
/* eslint-disable max-params */
 
'use strict';
 
// MODULES //
 
var isRowMajor = require( '@stdlib/ndarray/base/assert/is-row-major' );
var dfill = require( '@stdlib/blas/ext/base/dfill' ).ndarray;
var dcopy = require( '@stdlib/blas/base/dcopy' ).ndarray;
 
 
// MAIN //
 
/**
* Computes the Cartesian product for two double-precision floating-point strided arrays using alternative indexing semantics.
*
* ## Notes
*
* -   Pairs are stored as rows in the output matrix, where the first column contains the first element of each pair and the second column contains the second element.
*
* @param {NonNegativeInteger} M - number of indexed elements in `x`
* @param {NonNegativeInteger} N - number of indexed elements in `y`
* @param {Float64Array} x - first input array
* @param {integer} strideX - stride length for `x`
* @param {NonNegativeInteger} offsetX - starting index for `x`
* @param {Float64Array} y - second input array
* @param {integer} strideY - stride length for `y`
* @param {NonNegativeInteger} offsetY - starting index for `y`
* @param {Float64Array} out - output array
* @param {integer} strideOut1 - stride length for the first dimension of `out`
* @param {integer} strideOut2 - stride length for the second dimension of `out`
* @param {NonNegativeInteger} offsetOut - starting index for `out`
* @returns {Float64Array} output array
*
* @example
* var Float64Array = require( '@stdlib/array/float64' );
*
* var x = new Float64Array( [ 1.0, 2.0 ] );
* var y = new Float64Array( [ 3.0, 4.0 ] );
* var out = new Float64Array( 8 );
*
* dcartesianProduct( x.length, y.length, x, 1, 0, y, 1, 0, out, 2, 1, 0 );
* // out => <Float64Array>[ 1.0, 3.0, 1.0, 4.0, 2.0, 3.0, 2.0, 4.0 ]
*/
function dcartesianProduct( M, N, x, strideX, offsetX, y, strideY, offsetY, out, strideOut1, strideOut2, offsetOut ) { // eslint-disable-line max-len
	var iy;
	var ix;
	var io;
	var v;
	var i;
	var j;

	if ( M <= 0 || N <= 0 ) {
		return out;
	}
	ix = offsetX;
	io = offsetOut;
	if ( isRowMajor( [ strideOut1, strideOut2 ] ) ) {
		for ( i = 0; i < M; i++ ) {
			v = x[ ix ];
			iy = offsetY;
			for ( j = 0; j < N; j++ ) {
				out[ io ] = v;
				out[ io + strideOut2 ] = y[ iy ];
				iy += strideY;
				io += strideOut1;
			}
			ix += strideX;
		}
		return out;
	}
	// Column-major...
	for ( i = 0; i < M; i++ ) {
		dfill( N, x[ ix ], out, strideOut1, io );
		io += N * strideOut1;
		ix += strideX;
	}
	io = offsetOut + strideOut2;
	for ( i = 0; i < M; i++ ) {
		dcopy( N, y, strideY, offsetY, out, strideOut1, io );
		io += N * strideOut1;
	}
	return out;
}
 
 
// EXPORTS //
 
module.exports = dcartesianProduct;