time-to-botec/squiggle/node_modules/@stdlib/number/float64/base/exponent/README.md

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@license Apache-2.0
Copyright (c) 2018 The Stdlib Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
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# Exponent
> Return an integer corresponding to the unbiased exponent of a [double-precision floating-point number][ieee754].
<section class="usage">
## Usage
```javascript
var exponent = require( '@stdlib/number/float64/base/exponent' );
```
#### exponent( x )
Returns an `integer` corresponding to the unbiased exponent of a [double-precision floating-point number][ieee754].
```javascript
var exp = exponent( 3.14e307 ); // => 2**1021 ~ 1e307
// returns 1021
exp = exponent( 3.14e-307 ); // => 2**-1019 ~ 1e-307
// returns -1019
exp = exponent( -3.14 );
// returns 1
exp = exponent( 0.0 );
// returns -1023
exp = exponent( NaN );
// returns 1024
```
</section>
<!-- /.usage -->
<section class="examples">
## Examples
<!-- eslint no-undef: "error" -->
```javascript
var randu = require( '@stdlib/random/base/randu' );
var round = require( '@stdlib/math/base/special/round' );
var pow = require( '@stdlib/math/base/special/pow' );
var exponent = require( '@stdlib/number/float64/base/exponent' );
var frac;
var exp;
var x;
var e;
var i;
// Generate random numbers and extract their exponents...
for ( i = 0; i < 100; i++ ) {
frac = randu() * 10.0;
exp = round( randu()*646.0 ) - 323;
x = frac * pow( 10.0, exp );
e = exponent( x );
console.log( 'x: %d. unbiased exponent: %d.', x, e );
}
```
</section>
<!-- /.examples -->
<section class="links">
[ieee754]: https://en.wikipedia.org/wiki/IEEE_754-1985
</section>
<!-- /.links -->