time-to-botec

Benchmark sampling in different programming languages
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README.md (3856B)

      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 # From Binary String
     22 
     23 > Create a [double-precision floating-point number][ieee754] from a [literal bit representation][@stdlib/number/float64/base/to-binary-string].
     24 
     25 <section class="usage">
     26 
     27 ## Usage
     28 
     29 ```javascript
     30 var fromBinaryString = require( '@stdlib/number/float64/base/from-binary-string' );
     31 ```
     32 
     33 #### fromBinaryString( bstr )
     34 
     35 Creates a [double-precision floating-point number][ieee754] from a [literal bit representation][@stdlib/number/float64/base/to-binary-string].
     36 
     37 ```javascript
     38 var bstr = '0100000000010000000000000000000000000000000000000000000000000000';
     39 var val = fromBinaryString( bstr );
     40 // returns 4.0
     41 
     42 bstr = '0100000000001001001000011111101101010100010001000010110100011000';
     43 val = fromBinaryString( bstr );
     44 // returns 3.141592653589793
     45 
     46 bstr = '1111111111100001110011001111001110000101111010111100100010100000';
     47 val = fromBinaryString( bstr );
     48 // returns -1.0e308
     49 ```
     50 
     51 The function handles [subnormals][subnormals].
     52 
     53 ```javascript
     54 var bstr = '1000000000000000000000000000000000000000000000000001100011010011';
     55 var val = fromBinaryString( bstr );
     56 // returns -3.14e-320
     57 
     58 bstr = '0000000000000000000000000000000000000000000000000000000000000001';
     59 val = fromBinaryString( bstr );
     60 // returns 5.0e-324
     61 ```
     62 
     63 The function handles special values.
     64 
     65 ```javascript
     66 var bstr = '0000000000000000000000000000000000000000000000000000000000000000';
     67 var val = fromBinaryString( bstr );
     68 // returns 0.0
     69 
     70 bstr = '1000000000000000000000000000000000000000000000000000000000000000';
     71 val = fromBinaryString( bstr );
     72 // returns -0.0
     73 
     74 bstr = '0111111111111000000000000000000000000000000000000000000000000000';
     75 val = fromBinaryString( bstr );
     76 // returns NaN
     77 
     78 bstr = '0111111111110000000000000000000000000000000000000000000000000000';
     79 val = fromBinaryString( bstr );
     80 // returns Infinity
     81 
     82 bstr = '1111111111110000000000000000000000000000000000000000000000000000';
     83 val = fromBinaryString( bstr );
     84 // returns -Infinity
     85 ```
     86 
     87 </section>
     88 
     89 <!-- /.usage -->
     90 
     91 <section class="examples">
     92 
     93 ## Examples
     94 
     95 <!-- eslint no-undef: "error" -->
     96 
     97 ```javascript
     98 var randu = require( '@stdlib/random/base/randu' );
     99 var round = require( '@stdlib/math/base/special/round' );
    100 var pow = require( '@stdlib/math/base/special/pow' );
    101 var toBinaryString = require( '@stdlib/number/float64/base/to-binary-string' );
    102 var fromBinaryString = require( '@stdlib/number/float64/base/from-binary-string' );
    103 
    104 var frac;
    105 var sign;
    106 var exp;
    107 var b;
    108 var x;
    109 var y;
    110 var i;
    111 
    112 // Convert random numbers to literal bit representations and then convert them back...
    113 for ( i = 0; i < 100; i++ ) {
    114     if ( randu() < 0.5 ) {
    115         sign = -1.0;
    116     } else {
    117         sign = 1.0;
    118     }
    119     frac = randu() * 10.0;
    120     exp = round( randu()*100.0 );
    121     if ( randu() < 0.5 ) {
    122         exp = -exp;
    123     }
    124     x = sign * frac * pow( 2.0, exp );
    125     b = toBinaryString( x );
    126     y = fromBinaryString( b );
    127     console.log( '%d => %s => %d', x, b, y );
    128     console.log( x === y );
    129 }
    130 ```
    131 
    132 </section>
    133 
    134 <!-- /.examples -->
    135 
    136 <section class="links">
    137 
    138 [ieee754]: https://en.wikipedia.org/wiki/IEEE_754-1985
    139 
    140 [subnormals]: https://en.wikipedia.org/wiki/Denormal_number
    141 
    142 [@stdlib/number/float64/base/to-binary-string]: https://www.npmjs.com/package/@stdlib/number/tree/main/float64/base/to-binary-string
    143 
    144 </section>
    145 
    146 <!-- /.links -->