time-to-botec

Benchmark sampling in different programming languages
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README.md (2155B)

      1 <!--
      2 
      3 @license Apache-2.0
      4 
      5 Copyright (c) 2018 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 # roundn
     22 
     23 > Round a numeric value to the nearest multiple of 10^n.
     24 
     25 <section class="usage">
     26 
     27 ## Usage
     28 
     29 ```javascript
     30 var roundn = require( '@stdlib/math/base/special/roundn' );
     31 ```
     32 
     33 #### roundn( x, n )
     34 
     35 Rounds a `numeric` value to the nearest multiple of `10^n`.
     36 
     37 ```javascript
     38 // Round a value to 2 decimal places:
     39 var v = roundn( 3.141592653589793, -2 );
     40 // returns 3.14
     41 
     42 // If n = 0, `roundn` behaves like `round`:
     43 v = roundn( 3.141592653589793, 0 );
     44 // returns 3.0
     45 
     46 // Round a value to the nearest thousand:
     47 v = roundn( 12368.0, 3 );
     48 // returns 12000.0
     49 ```
     50 
     51 </section>
     52 
     53 <!-- /.usage -->
     54 
     55 <section class="notes">
     56 
     57 ## Notes
     58 
     59 -   When operating on [floating-point numbers][ieee754] in bases other than `2`, rounding to specified digits can be **inexact**. For example,
     60 
     61     ```javascript
     62     var x = 0.2 + 0.1;
     63     // returns 0.30000000000000004
     64 
     65     // Should round to 0.3...
     66     var v = roundn( x, -16 );
     67     // returns 0.3000000000000001
     68     ```
     69 
     70 </section>
     71 
     72 <!-- /.notes -->
     73 
     74 <section class="examples">
     75 
     76 ## Examples
     77 
     78 <!-- eslint no-undef: "error" -->
     79 
     80 ```javascript
     81 var randu = require( '@stdlib/random/base/randu' );
     82 var roundn = require( '@stdlib/math/base/special/roundn' );
     83 
     84 var x;
     85 var n;
     86 var v;
     87 var i;
     88 
     89 for ( i = 0; i < 100; i++ ) {
     90     x = (randu()*100.0) - 50.0;
     91     n = roundn( randu()*5.0, 0 );
     92     v = roundn( x, -n );
     93     console.log( 'x: %d. Number of decimals: %d. Rounded: %d.', x, n, v );
     94 }
     95 ```
     96 
     97 </section>
     98 
     99 <!-- /.examples -->
    100 
    101 <section class="links">
    102 
    103 [ieee754]: https://en.wikipedia.org/wiki/IEEE_754-1985
    104 
    105 </section>
    106 
    107 <!-- /.links -->