time-to-botec

Benchmark sampling in different programming languages
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README.md (4419B)

      1 <!--
      2 
      3 @license Apache-2.0
      4 
      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
     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.
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     19 -->
     20 
     21 # dmaxsorted
     22 
     23 > Calculate the maximum value of a sorted double-precision floating-point strided array.
     24 
     25 <section class="intro">
     26 
     27 </section>
     28 
     29 <!-- /.intro -->
     30 
     31 <section class="usage">
     32 
     33 ## Usage
     34 
     35 ```javascript
     36 var dmaxsorted = require( '@stdlib/stats/base/dmaxsorted' );
     37 ```
     38 
     39 #### dmaxsorted( N, x, stride )
     40 
     41 Computes the maximum value of a sorted double-precision floating-point strided array `x`.
     42 
     43 ```javascript
     44 var Float64Array = require( '@stdlib/array/float64' );
     45 
     46 var x = new Float64Array( [ 1.0, 2.0, 3.0 ] );
     47 var N = x.length;
     48 
     49 var v = dmaxsorted( N, x, 1 );
     50 // returns 3.0
     51 
     52 x = new Float64Array( [ 3.0, 2.0, 1.0 ] );
     53 N = x.length;
     54 
     55 v = dmaxsorted( N, x, 1 );
     56 // returns 3.0
     57 ```
     58 
     59 The function has the following parameters:
     60 
     61 -   **N**: number of indexed elements.
     62 -   **x**: sorted input [`Float64Array`][@stdlib/array/float64].
     63 -   **stride**: index increment for `x`.
     64 
     65 The `N` and `stride` parameters determine which elements in `x` are accessed at runtime. For example, to compute the maximum value of every other element in `x`,
     66 
     67 ```javascript
     68 var Float64Array = require( '@stdlib/array/float64' );
     69 var floor = require( '@stdlib/math/base/special/floor' );
     70 
     71 var x = new Float64Array( [ 1.0, 2.0, 2.0, -7.0, 3.0, 3.0, 4.0, 2.0 ] );
     72 var N = floor( x.length / 2 );
     73 
     74 var v = dmaxsorted( N, x, 2 );
     75 // returns 4.0
     76 ```
     77 
     78 Note that indexing is relative to the first index. To introduce an offset, use [`typed array`][mdn-typed-array] views.
     79 
     80 <!-- eslint-disable stdlib/capitalized-comments -->
     81 
     82 ```javascript
     83 var Float64Array = require( '@stdlib/array/float64' );
     84 var floor = require( '@stdlib/math/base/special/floor' );
     85 
     86 var x0 = new Float64Array( [ 2.0, 1.0, 2.0, 2.0, -2.0, 2.0, 3.0, 4.0 ] );
     87 var x1 = new Float64Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element
     88 
     89 var N = floor( x0.length / 2 );
     90 
     91 var v = dmaxsorted( N, x1, 2 );
     92 // returns 4.0
     93 ```
     94 
     95 #### dmaxsorted.ndarray( N, x, stride, offset )
     96 
     97 Computes the maximum value of a sorted double-precision floating-point strided array using alternative indexing semantics.
     98 
     99 ```javascript
    100 var Float64Array = require( '@stdlib/array/float64' );
    101 
    102 var x = new Float64Array( [ 1.0, 2.0, 3.0 ] );
    103 var N = x.length;
    104 
    105 var v = dmaxsorted.ndarray( N, x, 1, 0 );
    106 // returns 3.0
    107 ```
    108 
    109 The function has the following additional parameters:
    110 
    111 -   **offset**: starting index for `x`.
    112 
    113 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 maximum value for every other value in `x` starting from the second value
    114 
    115 ```javascript
    116 var Float64Array = require( '@stdlib/array/float64' );
    117 var floor = require( '@stdlib/math/base/special/floor' );
    118 
    119 var x = new Float64Array( [ 2.0, 1.0, 2.0, 2.0, -2.0, 2.0, 3.0, 4.0 ] );
    120 var N = floor( x.length / 2 );
    121 
    122 var v = dmaxsorted.ndarray( N, x, 2, 1 );
    123 // returns 4.0
    124 ```
    125 
    126 </section>
    127 
    128 <!-- /.usage -->
    129 
    130 <section class="notes">
    131 
    132 ## Notes
    133 
    134 -   If `N <= 0`, both functions return `NaN`.
    135 -   The input strided array must be sorted in either **strictly** ascending or descending order.
    136 
    137 </section>
    138 
    139 <!-- /.notes -->
    140 
    141 <section class="examples">
    142 
    143 ## Examples
    144 
    145 <!-- eslint no-undef: "error" -->
    146 
    147 ```javascript
    148 var Float64Array = require( '@stdlib/array/float64' );
    149 var dmaxsorted = require( '@stdlib/stats/base/dmaxsorted' );
    150 
    151 var x;
    152 var i;
    153 
    154 x = new Float64Array( 10 );
    155 for ( i = 0; i < x.length; i++ ) {
    156     x[ i ] = i - 5.0;
    157 }
    158 console.log( x );
    159 
    160 var v = dmaxsorted( x.length, x, 1 );
    161 console.log( v );
    162 ```
    163 
    164 </section>
    165 
    166 <!-- /.examples -->
    167 
    168 <section class="links">
    169 
    170 [@stdlib/array/float64]: https://www.npmjs.com/package/@stdlib/array-float64
    171 
    172 [mdn-typed-array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray
    173 
    174 </section>
    175 
    176 <!-- /.links -->