npm package: @stdlib/number-float16-base-exponent
Description: Return an integer corresponding to the unbiased exponent of a half-precision floating-point number.
Author: The Stdlib Authors
Latest version: 0.1.1

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# exponent

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> Return an integer corresponding to the unbiased exponent of a [half-precision floating-point number][ieee754].

<section class="installation">

## Installation

```bash
npm install @stdlib/number-float16-base-exponent
```

</section>

<section class="usage">

## Usage

```javascript
var exponent = require( '@stdlib/number-float16-base-exponent' );
```

#### exponent( x )

Returns an integer corresponding to the unbiased exponent of a [half-precision floating-point number][ieee754].

```javascript
var toFloat16 = require( '@stdlib/number-float64-base-to-float16' );

var exp = exponent( toFloat16( 3.14e4 ) ); // => 2^15 ≈ 3.27e4
// returns 15

exp = exponent( toFloat16( 3.14e-4 ) ); // => 2^-12 ≈ 2.44e-4
// returns -12

exp = exponent( toFloat16( -3.14 ) );
// returns 1

exp = exponent( 0.0 );
// returns -15

exp = exponent( NaN );
// returns 16
```

</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 toFloat16 = require( '@stdlib/number-float64-base-to-float16' );
var exponent = require( '@stdlib/number-float16-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()*13.0 ) - 7;
    x = frac * pow( 10.0, exp );
    x = toFloat16( x );
    e = exponent( x );
    console.log( 'x: %d. unbiased exponent: %d.', x, e );
}
```

</section>

<!-- /.examples -->

<!-- C interface documentation. -->

* * *

<section class="c">

## C APIs

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<section class="intro">

</section>

<!-- /.intro -->

<!-- C usage documentation. -->

<section class="usage">

### Usage

```c
#include "stdlib/number/float16/base/exponent.h"
```

#### stdlib_base_float16_exponent( x )

Returns an integer corresponding to the unbiased exponent of a [half-precision floating-point number][ieee754].

```c
#include "stdlib/number/float16/ctor.h"
#include <stdint.h>

stdlib_float16_t x = stdlib_float16_from_bits( 51648 ); // => -11.5
int16_t out = stdlib_base_float16_exponent( x );
```

The function accepts the following arguments:

-   **x**: `[in] stdlib_float16_t` input value.

```c
int16_t stdlib_base_float16_exponent( const stdlib_float16_t x );
```

</section>

<!-- /.usage -->

<!-- C API usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="notes">

</section>

<!-- /.notes -->

<!-- C API usage examples. -->

<section class="examples">

### Examples

```c
#include "stdlib/number/float16/base/exponent.h"
#include "stdlib/number/float16/ctor.h"
#include "stdlib/number/float32/base/to_float16.h"
#include <stdint.h>
#include <stdio.h>
#include <inttypes.h>

int main( void ) {
    const float x[] = { 4.0f, 0.0f, -0.0f, 1.0f, -1.0f, 3.14f, -3.14f, 1.0e38f, -1.0e38f, 1.0f/0.0f, -1.0f/0.0f, 0.0f/0.0f };

    stdlib_float16_t v;
    int16_t out;
    int i;
    for ( i = 0; i < 12; i++ ) {
        v = stdlib_base_float32_to_float16( x[ i ] );
        out = stdlib_base_float16_exponent( v );
        printf( "%f => out: %" PRId16 "\n", x[ i ], out );
    }
}
```

</section>

<!-- /.examples -->

</section>

<!-- /.c -->

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<section class="related">

</section>

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<section class="main-repo" >

* * *

## Notice

This package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].

#### Community

[![Chat][chat-image]][chat-url]

---

## License

See [LICENSE][stdlib-license].


## Copyright

Copyright &copy; 2016-2026. The Stdlib [Authors][stdlib-authors].

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[umd]: https://github.com/umdjs/umd
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[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/number-float16-base-exponent/main/LICENSE

[ieee754]: https://en.wikipedia.org/wiki/IEEE_754-1985

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</section>

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