time-to-botec

Benchmark sampling in different programming languages
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README.md (5982B)

      1 <!--
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      3 @license Apache-2.0
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      5 Copyright (c) 2020 The Stdlib Authors.
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      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
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     11    http://www.apache.org/licenses/LICENSE-2.0
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     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
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     19 -->
     20 
     21 # dsnannsumors
     22 
     23 > Calculate the sum of single-precision floating-point strided array elements, ignoring `NaN` values, using ordinary recursive summation with extended accumulation, and returning an extended precision result.
     24 
     25 <section class="intro">
     26 
     27 </section>
     28 
     29 <!-- /.intro -->
     30 
     31 <section class="usage">
     32 
     33 ## Usage
     34 
     35 ```javascript
     36 var dsnannsumors = require( '@stdlib/blas/ext/base/dsnannsumors' );
     37 ```
     38 
     39 #### dsnannsumors( N, x, strideX, out, strideOut )
     40 
     41 Computes the sum of single-precision floating-point strided array elements, ignoring `NaN` values, using ordinary recursive summation with extended accumulation, and returning an extended precision result.
     42 
     43 ```javascript
     44 var Float32Array = require( '@stdlib/array/float32' );
     45 var Float64Array = require( '@stdlib/array/float64' );
     46 
     47 var x = new Float32Array( [ 1.0, -2.0, NaN, 2.0 ] );
     48 var out = new Float64Array( 2 );
     49 
     50 var v = dsnannsumors( x.length, x, 1, out, 1 );
     51 // returns <Float64Array>[ 1.0, 3 ]
     52 ```
     53 
     54 The function has the following parameters:
     55 
     56 -   **N**: number of indexed elements.
     57 -   **x**: input [`Float32Array`][@stdlib/array/float32].
     58 -   **strideX**: index increment for `x`.
     59 -   **out**: output [`Float64Array`][@stdlib/array/float64] whose first element is the sum and whose second element is the number of non-NaN elements.
     60 -   **strideOut**: index increment for `out`.
     61 
     62 The `N` and `stride` parameters determine which elements are accessed at runtime. For example, to compute the sum of every other element in `x`,
     63 
     64 ```javascript
     65 var Float32Array = require( '@stdlib/array/float32' );
     66 var Float64Array = require( '@stdlib/array/float64' );
     67 var floor = require( '@stdlib/math/base/special/floor' );
     68 
     69 var x = new Float32Array( [ 1.0, 2.0, NaN, -7.0, NaN, 3.0, 4.0, 2.0 ] );
     70 var out = new Float64Array( 2 );
     71 var N = floor( x.length / 2 );
     72 
     73 var v = dsnannsumors( N, x, 2, out, 1 );
     74 // returns <Float64Array>[ 5.0, 2 ]
     75 ```
     76 
     77 Note that indexing is relative to the first index. To introduce an offset, use [`typed array`][mdn-typed-array] views.
     78 
     79 <!-- eslint-disable stdlib/capitalized-comments -->
     80 
     81 ```javascript
     82 var Float32Array = require( '@stdlib/array/float32' );
     83 var Float64Array = require( '@stdlib/array/float64' );
     84 var floor = require( '@stdlib/math/base/special/floor' );
     85 
     86 var x0 = new Float32Array( [ 2.0, 1.0, NaN, -2.0, -2.0, 2.0, 3.0, 4.0 ] );
     87 var x1 = new Float32Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element
     88 
     89 var out0 = new Float64Array( 4 );
     90 var out1 = new Float64Array( out0.buffer, out0.BYTES_PER_ELEMENT*2 ); // start at 3rd element
     91 
     92 var N = floor( x0.length / 2 );
     93 
     94 var v = dsnannsumors( N, x1, 2, out1, 1 );
     95 // returns <Float64Array>[ 5.0, 4 ]
     96 ```
     97 
     98 #### dsnannsumors.ndarray( N, x, strideX, offsetX, out, strideOut, offsetOut )
     99 
    100 Computes the sum of single-precision floating-point strided array elements, ignoring `NaN` values and using ordinary recursive summation with extended accumulation and alternative indexing semantics.
    101 
    102 ```javascript
    103 var Float32Array = require( '@stdlib/array/float32' );
    104 var Float64Array = require( '@stdlib/array/float64' );
    105 
    106 var x = new Float32Array( [ 1.0, -2.0, NaN, 2.0 ] );
    107 var out = new Float64Array( 2 );
    108 
    109 var v = dsnannsumors.ndarray( x.length, x, 1, 0, out, 1, 0 );
    110 // returns <Float64Array>[ 1.0, 3 ]
    111 ```
    112 
    113 The function has the following additional parameters:
    114 
    115 -   **offsetX**: starting index for `x`.
    116 -   **offsetOut**: starting index for `out`.
    117 
    118 While [`typed array`][mdn-typed-array] views mandate a view offset based on the underlying `buffer`, the `offset` parameter supports indexing semantics based on a starting index. For example, to calculate the sum of every other value in `x` starting from the second value
    119 
    120 ```javascript
    121 var Float32Array = require( '@stdlib/array/float32' );
    122 var Float64Array = require( '@stdlib/array/float64' );
    123 var floor = require( '@stdlib/math/base/special/floor' );
    124 
    125 var x = new Float32Array( [ 2.0, 1.0, NaN, -2.0, -2.0, 2.0, 3.0, 4.0 ] );
    126 var out = new Float64Array( 4 );
    127 var N = floor( x.length / 2 );
    128 
    129 var v = dsnannsumors.ndarray( N, x, 2, 1, out, 2, 1 );
    130 // returns <Float64Array>[ 0.0, 5.0, 0.0, 4 ]
    131 ```
    132 
    133 </section>
    134 
    135 <!-- /.usage -->
    136 
    137 <section class="notes">
    138 
    139 ## Notes
    140 
    141 -   If `N <= 0`, both functions return a sum equal to `0.0`.
    142 -   Accumulated intermediate values are stored as double-precision floating-point numbers.
    143 
    144 </section>
    145 
    146 <!-- /.notes -->
    147 
    148 <section class="examples">
    149 
    150 ## Examples
    151 
    152 <!-- eslint no-undef: "error" -->
    153 
    154 ```javascript
    155 var randu = require( '@stdlib/random/base/randu' );
    156 var round = require( '@stdlib/math/base/special/round' );
    157 var Float32Array = require( '@stdlib/array/float32' );
    158 var Float64Array = require( '@stdlib/array/float64' );
    159 var dsnannsumors = require( '@stdlib/blas/ext/base/dsnannsumors' );
    160 
    161 var x;
    162 var i;
    163 
    164 x = new Float32Array( 10 );
    165 for ( i = 0; i < x.length; i++ ) {
    166     if ( randu() < 0.2 ) {
    167         x[ i ] = NaN;
    168     } else {
    169         x[ i ] = round( randu()*100.0 );
    170     }
    171 }
    172 console.log( x );
    173 
    174 var out = new Float64Array( 2 );
    175 dsnannsumors( x.length, x, 1, out, 1 );
    176 console.log( out );
    177 ```
    178 
    179 </section>
    180 
    181 <!-- /.examples -->
    182 
    183 <section class="links">
    184 
    185 [@stdlib/array/float32]: https://www.npmjs.com/package/@stdlib/array-float32
    186 
    187 [@stdlib/array/float64]: https://www.npmjs.com/package/@stdlib/array-float64
    188 
    189 [mdn-typed-array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray
    190 
    191 </section>
    192 
    193 <!-- /.links -->