time-to-botec

Benchmark sampling in different programming languages
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README.md (3731B)

      1 <!--
      2 
      3 @license Apache-2.0
      4 
      5 Copyright (c) 2020 The Stdlib Authors.
      6 
      7 Licensed under the Apache License, Version 2.0 (the "License");
      8 you may not use this file except in compliance with the License.
      9 You may obtain a copy of the License at
     10 
     11    http://www.apache.org/licenses/LICENSE-2.0
     12 
     13 Unless required by applicable law or agreed to in writing, software
     14 distributed under the License is distributed on an "AS IS" BASIS,
     15 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     16 See the License for the specific language governing permissions and
     17 limitations under the License.
     18 
     19 -->
     20 
     21 # ddot
     22 
     23 > Calculate the dot product of two double-precision floating-point vectors.
     24 
     25 <section class="intro">
     26 
     27 The [dot product][dot-product] (or scalar product) is defined as
     28 
     29 <!-- <equation class="equation" label="eq:dot_product" align="center" raw="\mathbf{x}\cdot\mathbf{y} = \sum_{i=0}^{N-1} x_i y_i = x_0 y_0 + x_1 y_1 + \ldots + x_{N-1} y_{N-1}" alt="Dot product definition."> -->
     30 
     31 <div class="equation" align="center" data-raw-text="\mathbf{x}\cdot\mathbf{y} = \sum_{i=0}^{N-1} x_i y_i = x_0 y_0 + x_1 y_1 + \ldots + x_{N-1} y_{N-1}" data-equation="eq:dot_product">
     32     <img src="https://cdn.jsdelivr.net/gh/stdlib-js/stdlib@d0afc603cdda35b11d5bd1633dd4dddb0d59e117/lib/node_modules/@stdlib/blas/ddot/docs/img/equation_dot_product.svg" alt="Dot product definition.">
     33     <br>
     34 </div>
     35 
     36 <!-- </equation> -->
     37 
     38 </section>
     39 
     40 <!-- /.intro -->
     41 
     42 <section class="usage">
     43 
     44 ## Usage
     45 
     46 ```javascript
     47 var ddot = require( '@stdlib/blas/ddot' );
     48 ```
     49 
     50 #### ddot( x, y )
     51 
     52 Calculates the dot product of two double-precision floating-point vectors `x` and `y`.
     53 
     54 ```javascript
     55 var Float64Array = require( '@stdlib/array/float64' );
     56 var array = require( '@stdlib/ndarray/array' );
     57 
     58 var x = array( new Float64Array( [ 4.0, 2.0, -3.0, 5.0, -1.0 ] ) );
     59 var y = array( new Float64Array( [ 2.0, 6.0, -1.0, -4.0, 8.0 ] ) );
     60 
     61 var z = ddot( x, y );
     62 // returns -5.0
     63 ```
     64 
     65 The function has the following parameters:
     66 
     67 -   **x**: a 1-dimensional [`ndarray`][@stdlib/ndarray/array] whose underlying data type is `float64`.
     68 -   **y**: a 1-dimensional [`ndarray`][@stdlib/ndarray/array] whose underlying data type is `float64`.
     69 
     70 If provided empty vectors, the function returns `0.0`.
     71 
     72 ```javascript
     73 var Float64Array = require( '@stdlib/array/float64' );
     74 var array = require( '@stdlib/ndarray/array' );
     75 
     76 var x = array( new Float64Array() );
     77 var y = array( new Float64Array() );
     78 
     79 var z = ddot( x, y );
     80 // returns 0.0
     81 ```
     82 
     83 </section>
     84 
     85 <!-- /.usage -->
     86 
     87 <section class="notes">
     88 
     89 ## Notes
     90 
     91 -   `ddot()` provides a higher-level interface to the [BLAS][blas] level 1 function [`ddot`][@stdlib/blas/base/ddot].
     92 
     93 </section>
     94 
     95 <!-- /.notes -->
     96 
     97 <section class="examples">
     98 
     99 ## Examples
    100 
    101 <!-- eslint no-undef: "error" -->
    102 
    103 ```javascript
    104 var discreteUniform = require( '@stdlib/random/base/discrete-uniform' );
    105 var Float64Array = require( '@stdlib/array/float64' );
    106 var array = require( '@stdlib/ndarray/array' );
    107 var ddot = require( '@stdlib/blas/ddot' );
    108 
    109 var x = array( new Float64Array( 10 ) );
    110 var y = array( new Float64Array( 10 ) );
    111 
    112 var rand1 = discreteUniform.factory( 0, 100 );
    113 var rand2 = discreteUniform.factory( 0, 10 );
    114 
    115 var i;
    116 for ( i = 0; i < x.length; i++ ) {
    117     x.set( i, rand1() );
    118     y.set( i, rand2() );
    119 }
    120 console.log( x.toString() );
    121 console.log( y.toString() );
    122 
    123 var z = ddot( x, y );
    124 console.log( z );
    125 ```
    126 
    127 </section>
    128 
    129 <!-- /.examples -->
    130 
    131 <section class="links">
    132 
    133 [dot-product]: https://en.wikipedia.org/wiki/Dot_product
    134 
    135 [blas]: http://www.netlib.org/blas
    136 
    137 [@stdlib/blas/base/ddot]: https://www.npmjs.com/package/@stdlib/blas/tree/main/base/ddot
    138 
    139 [@stdlib/ndarray/array]: https://www.npmjs.com/package/@stdlib/ndarray-array
    140 
    141 </section>
    142 
    143 <!-- /.links -->