time-to-botec

Benchmark sampling in different programming languages
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README.md (4474B)

      1 <!--
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      3 @license Apache-2.0
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      5 Copyright (c) 2021 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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     20 
     21 # Datespace
     22 
     23 > Generate an array of linearly spaced [dates][mdn-date-object].
     24 
     25 <section class="usage">
     26 
     27 ## Usage
     28 
     29 ```javascript
     30 var datespace = require( '@stdlib/array/datespace' );
     31 ```
     32 
     33 #### datespace( start, stop\[, length]\[, opts] )
     34 
     35 Generates an `array` of linearly spaced [`Date`][mdn-date-object] objects. If a `length` is not provided, the default output `array` length is `100`.
     36 
     37 ```javascript
     38 var end = '2014-12-02T07:00:54.973Z';
     39 var start = new Date( end ) - 60000;
     40 
     41 var arr = datespace( start, end, 6 );
     42 /* returns [
     43     'Mon Dec 01 2014 22:59:54 GMT-0800 (PST)',
     44     'Mon Dec 01 2014 23:00:06 GMT-0800 (PST)',
     45     'Mon Dec 01 2014 23:00:18 GMT-0800 (PST)',
     46     'Mon Dec 01 2014 23:00:30 GMT-0800 (PST)',
     47     'Mon Dec 01 2014 23:00:42 GMT-0800 (PST)',
     48     'Mon Dec 01 2014 23:00:54 GMT-0800 (PST)'
     49 ]
     50 */
     51 ```
     52 
     53 The `start` and `stop` times may be either [`Date`][mdn-date-object] objects, date strings, Unix timestamps, or JavaScript timestamps.
     54 
     55 ```javascript
     56 // JavaScript timestamps:
     57 var end = 1417503654973;
     58 var start = new Date( end - 60000 );
     59 
     60 var arr = datespace( start, end, 6 );
     61 /* returns [
     62     'Mon Dec 01 2014 22:59:54 GMT-0800 (PST)',
     63     'Mon Dec 01 2014 23:00:06 GMT-0800 (PST)',
     64     'Mon Dec 01 2014 23:00:18 GMT-0800 (PST)',
     65     'Mon Dec 01 2014 23:00:30 GMT-0800 (PST)',
     66     'Mon Dec 01 2014 23:00:42 GMT-0800 (PST)',
     67     'Mon Dec 01 2014 23:00:54 GMT-0800 (PST)'
     68 ]
     69 */
     70 
     71 // Unix timestamps:
     72 end = 1417503655;
     73 start = end - 60;
     74 
     75 arr = datespace( start, end, 6 );
     76 /* returns [
     77     'Mon Dec 01 2014 22:59:54 GMT-0800 (PST)',
     78     'Mon Dec 01 2014 23:00:06 GMT-0800 (PST)',
     79     'Mon Dec 01 2014 23:00:18 GMT-0800 (PST)',
     80     'Mon Dec 01 2014 23:00:30 GMT-0800 (PST)',
     81     'Mon Dec 01 2014 23:00:42 GMT-0800 (PST)',
     82     'Mon Dec 01 2014 23:00:54 GMT-0800 (PST)'
     83 ]
     84 */
     85 ```
     86 
     87 The output `array` is guaranteed to include the `start` and `end` times. Beware, however, that values between the `start` and `end` are subject to rounding errors. For example,
     88 
     89 ```javascript
     90 var arr = datespace( 1417503655000, 1417503655001, 3 );
     91 // returns [ 1417503655000, 1417503655000, 1417503655001 ]
     92 ```
     93 
     94 where sub-millisecond values are truncated by the [`Date`][mdn-date-object] constructor. Duplicate values should only be a problem when the interval separating consecutive times is less than a millisecond. As the interval separating consecutive dates goes to infinity, the quantization noise introduced by millisecond resolution is negligible.
     95 
     96 By default, fractional timestamps are floored. To specify that timestamps always be rounded up or to the nearest millisecond **when converted to [`Date`][mdn-date-object] objects**, set the `round` option (default: `floor`).
     97 
     98 ```javascript
     99 // Equivalent of Math.ceil():
    100 var arr = datespace( 1417503655000, 1417503655001, 3, {
    101     'round': 'ceil'
    102 });
    103 // returns [ 1417503655000, 1417503655001, 1417503655001 ]
    104 
    105 // Equivalent of Math.round():
    106 arr = datespace( 1417503655000, 1417503655001, 3, {
    107     'round': 'round'
    108 });
    109 // returns [ 1417503655000, 1417503655001, 1417503655001 ]
    110 ```
    111 
    112 </section>
    113 
    114 <!-- /.usage -->
    115 
    116 <section class="notes">
    117 
    118 </section>
    119 
    120 <!-- /.notes -->
    121 
    122 <section class="examples">
    123 
    124 ## Examples
    125 
    126 ```javascript
    127 var datespace = require( '@stdlib/array/datespace' );
    128 var start;
    129 var arr;
    130 var end;
    131 
    132 end = '2014-12-02T07:00:54.973Z';
    133 start = new Date( end ) - 100000;
    134 
    135 // Default behavior:
    136 arr = datespace( start, end );
    137 console.log( arr.join( '\n' ) );
    138 
    139 // Specify length:
    140 arr = datespace( start, end, 10 );
    141 console.log( arr.join( '\n' ) );
    142 
    143 arr = datespace( start, end, 11 );
    144 console.log( arr.join( '\n' ) );
    145 
    146 // Create an array with decremented values:
    147 arr = datespace( end, start, 11 );
    148 console.log( arr.join( '\n' ) );
    149 ```
    150 
    151 </section>
    152 
    153 <!-- /.examples -->
    154 
    155 <section class="links">
    156 
    157 [mdn-date-object]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date
    158 
    159 </section>
    160 
    161 <!-- /.links -->