npm package: @stdlib/number-float64-base-normalize
Description: Return a normal number `y` and exponent `exp` satisfying `x = y * 2^exp`.
Author: The Stdlib Authors
Latest version: 0.2.4

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<details>
  <summary>
    About stdlib...
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</details>

# normalize

[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url] <!-- [![dependencies][dependencies-image]][dependencies-url] -->

> Return a normal number `y` and exponent `exp` satisfying `x = y * 2^exp`.

<section class="installation">

## Installation

```bash
npm install @stdlib/number-float64-base-normalize
```

</section>

<section class="usage">

## Usage

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

#### normalize( x )

Returns a normal number `y` and exponent `exp` satisfying `x = y * 2^exp`.

```javascript
var pow = require( '@stdlib/math-base-special-pow' );

var out = normalize( 3.14e-319 );
// returns [ 1.4141234400356668e-303, -52 ]

var y = out[ 0 ];
var exp = out[ 1 ];

var bool = ( y*pow(2.0, exp) === 3.14e-319 );
// returns true
```

The function expects a finite, non-zero numeric value `x`. If `x == 0`,

```javascript
var out = normalize( 0.0 );
// returns [ 0.0, 0 ];
```

If `x` is either positive or negative `infinity` or `NaN`,

```javascript
var PINF = require( '@stdlib/constants-float64-pinf' );
var NINF = require( '@stdlib/constants-float64-ninf' );

var out = normalize( PINF );
// returns [ Infinity, 0 ]

out = normalize( NINF );
// returns [ -Infinity, 0 ]

out = normalize( NaN );
// returns [ NaN, 0 ]
```

#### normalize.assign( x, out, stride, offset )

Returns a normal number `y` and exponent `exp` satisfying `x = y * 2^exp` and assigns results to a provided output array.

```javascript
var Float64Array = require( '@stdlib/array-float64' );

var out = new Float64Array( 2 );

var v = normalize.assign( 3.14e-319, out, 1, 0);
// returns <Float64Array>[ 1.4141234400356668e-303, -52 ]

var bool = ( v === out );
// returns true
```

</section>

<!-- /.usage -->

<section class="examples">

## Examples

<!-- eslint no-undef: "error" -->

```javascript
var discreteUniform = require( '@stdlib/random-base-discrete-uniform' );
var randu = require( '@stdlib/random-base-uniform' );
var pow = require( '@stdlib/math-base-special-pow' );
var normalize = require( '@stdlib/number-float64-base-normalize' );

var frac;
var exp;
var x;
var v;
var i;

// Generate denormalized numbers and then normalize them...
for ( i = 0; i < 100; i++ ) {
    // Generate a random fraction:
    frac = randu( 0.0, 10.0 );

    // Generate an exponent on the interval (-308,-324):
    exp = discreteUniform( -323, -309 );

    // Create a subnormal number (~2.23e-308, ~4.94e-324):
    x = frac * pow( 10.0, exp );

    // Determine a `y` and an `exp` to "normalize" the subnormal:
    v = normalize( x );

    console.log( '%d = %d * 2^%d = %d', x, v[0], v[1], v[0]*pow(2.0, v[1]) );
}
```

</section>

<!-- /.examples -->

<!-- C interface documentation. -->

* * *

<section class="c">

## C APIs

<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->

<section class="intro">

</section>

<!-- /.intro -->

<!-- C usage documentation. -->

<section class="usage">

### Usage

```c
#include "stdlib/number/float64/base/normalize.h"
```

#### stdlib_base_float64_normalize( x, \*y, \*exp )

Returns a normal number `y` and exponent `exp` satisfying `x = y * 2^exp`.

```c
#include <stdint.h>

double y;
int32_t exp;

stdlib_base_float64_normalize( 3.14, &y, &exp );
```

The function accepts the following arguments:

-   **x**: `[in] double` input value.
-   **y**: `[out] double*` destination for normal number.
-   **exp**: `[out] int32_t*` destination for exponent.

```c
void stdlib_base_float64_normalize( const double x, double *y, int32_t *exp );
```

</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/float64/base/normalize.h"
#include <stdint.h>
#include <stdio.h>
#include <inttypes.h>

int main( void ) {
    double x[] = { 1.0, 3.14, 0.0, -0.0, 3.14e-308, 3.14e308, 1.0/0.0, 0.0/0.0 };
    int32_t exp;
    double y;
    int i;

    for ( i = 0; i < 8; i++ ) {
        stdlib_base_float64_normalize( x[ i ], &y, &exp );
        printf( "%lf => y: %lf, exp: %" PRId32 "\n", x[ i ], y, exp );
    }
}
```

</section>

<!-- /.examples -->

</section>

<!-- /.c -->

<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

* * *

## See Also

-   <span class="package-name">[`@stdlib/number-float32/base/normalize`][@stdlib/number/float32/base/normalize]</span><span class="delimiter">: </span><span class="description">return a normal number `y` and exponent `exp` satisfying `x = y * 2^exp`.</span>

</section>

<!-- /.related -->

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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].

</section>

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[@stdlib/number/float32/base/normalize]: https://www.npmjs.com/package/@stdlib/number-float32-base-normalize

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