/** * @license Apache-2.0 * * Copyright (c) 2019 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'; // MODULES // var float64ToFloat32 = require( '@stdlib/number/float64/base/to-float32' ); // MAIN // /** * Computes the dot product of `x` and `y`. * * @param {integer} N - number of values over which to compute the dot product * @param {Float32Array} x - first input array * @param {integer} strideX - `x` stride length * @param {NonNegativeInteger} offsetX - starting index for `x` * @param {Float32Array} y - second input array * @param {integer} strideY - `y` stride length * @param {NonNegativeInteger} offsetY - starting index for `y` * @returns {number} dot product of `x` and `y` * * @example * var Float32Array = require( '@stdlib/array/float32' ); * * var x = new Float32Array( [ 4.0, 2.0, -3.0, 5.0, -1.0 ] ); * var y = new Float32Array( [ 2.0, 6.0, -1.0, -4.0, 8.0 ] ); * * var z = sdot( x.length, x, 1, 0, y, 1, 0 ); * // returns -5.0 */ function sdot( N, x, strideX, offsetX, y, strideY, offsetY ) { var dot; var ix; var iy; var i; dot = 0.0; if ( N <= 0 ) { return dot; } ix = offsetX; iy = offsetY; for ( i = 0; i < N; i++ ) { dot = float64ToFloat32( dot + float64ToFloat32( x[ ix ] * y[ iy ] ) ); ix += strideX; iy += strideY; } return dot; } // EXPORTS // module.exports = sdot;