@stdlib/blas-ddot
v0.2.1
Published
Calculate the dot product of two double-precision floating-point vectors.
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ddot
Calculate the dot product of two double-precision floating-point vectors.
The dot product (or scalar product) is defined as
Installation
npm install @stdlib/blas-ddot
Usage
var ddot = require( '@stdlib/blas-ddot' );
ddot( x, y )
Calculates the dot product of two double-precision floating-point vectors x
and y
.
var Float64Array = require( '@stdlib/array-float64' );
var array = require( '@stdlib/ndarray-array' );
var x = array( new Float64Array( [ 4.0, 2.0, -3.0, 5.0, -1.0 ] ) );
var y = array( new Float64Array( [ 2.0, 6.0, -1.0, -4.0, 8.0 ] ) );
var z = ddot( x, y );
// returns -5.0
The function has the following parameters:
- x: a 1-dimensional
ndarray
whose underlying data type isfloat64
. - y: a 1-dimensional
ndarray
whose underlying data type isfloat64
.
If provided empty vectors, the function returns 0.0
.
var Float64Array = require( '@stdlib/array-float64' );
var array = require( '@stdlib/ndarray-array' );
var x = array( new Float64Array() );
var y = array( new Float64Array() );
var z = ddot( x, y );
// returns 0.0
Notes
Examples
var discreteUniform = require( '@stdlib/random-base-discrete-uniform' );
var Float64Array = require( '@stdlib/array-float64' );
var array = require( '@stdlib/ndarray-array' );
var ddot = require( '@stdlib/blas-ddot' );
var x = array( new Float64Array( 10 ) );
var y = array( new Float64Array( 10 ) );
var rand1 = discreteUniform.factory( 0, 100 );
var rand2 = discreteUniform.factory( 0, 10 );
var i;
for ( i = 0; i < x.length; i++ ) {
x.set( i, rand1() );
y.set( i, rand2() );
}
console.log( x.toString() );
console.log( y.toString() );
var z = ddot( x, y );
console.log( z );
See Also
@stdlib/blas-base/ddot
: calculate the dot product of two double-precision floating-point vectors.@stdlib/blas-gdot
: calculate the dot product of two vectors.@stdlib/blas-sdot
: calculate the dot product of two single-precision floating-point vectors.
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.