# normalizef
> Return a normal number `y` and exponent `exp` satisfying `x = y * 2^exp`.
## Usage
```javascript
var normalizef = require( '@stdlib/number/float32/base/normalize' );
```
#### normalizef( x )
Returns a normal number `y` and exponent `exp` satisfying `x = y * 2^exp`.
```javascript
var toFloat32 = require( '@stdlib/number/float64/base/to-float32' );
var out = normalizef( toFloat32( 1.401e-45 ) );
// returns [ 1.1754943508222875e-38, -23 ]
```
By default, the function returns `y` and `exp` as a two-element `array`.
```javascript
var toFloat32 = require( '@stdlib/number/float64/base/to-float32' );
var pow = require( '@stdlib/math/base/special/pow' );
var out = normalizef( toFloat32( 1.401e-45 ) );
// returns [ 1.1754943508222875e-38, -23 ]
var y = out[ 0 ];
var exp = out[ 1 ];
var bool = ( y*pow(2, exp) === toFloat32(1.401e-45) );
// returns true
```
The function expects a finite, non-zero [single-precision floating-point number][ieee754] `x`. If `x == 0`,
```javascript
var out = normalizef( 0.0 );
// returns [ 0.0, 0 ];
```
If `x` is either positive or negative `infinity` or `NaN`,
```javascript
var PINF = require( '@stdlib/constants/float32/pinf' );
var NINF = require( '@stdlib/constants/float32/ninf' );
var out = normalizef( PINF );
// returns [ Infinity, 0 ]
out = normalizef( NINF );
// returns [ -Infinity, 0 ]
out = normalizef( NaN );
// returns [ NaN, 0 ]
```
#### normalizef( 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 toFloat32 = require( '@stdlib/number/float64/base/to-float32' );
var Float32Array = require( '@stdlib/array/float32' );
var out = new Float32Array( 2 );
var v = normalizef.assign( toFloat32( 1.401e-45 ), out, 1, 0 );
// returns [ 1.1754943508222875e-38, -23 ]
var bool = ( v === out );
// returns true
```
## Notes
- While the function accepts higher precision [floating-point numbers][ieee754], beware that providing such numbers can be a source of subtle bugs as the relation `x = y * 2^exp` may **not** hold.
## Examples
```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 toFloat32 = require( '@stdlib/number/float64/base/to-float32' );
var normalizef = require( '@stdlib/number/float32/base/normalize' );
var frac;
var exp;
var x;
var v;
var i;
// Generate denormalized single-precision floating-point numbers and then normalize them...
for ( i = 0; i < 100; i++ ) {
frac = randu() * 10.0;
exp = 38 + round( randu()*6.0 );
x = frac * pow( 10.0, -exp );
x = toFloat32( x );
v = normalizef( x );
console.log( '%d = %d * 2^%d = %d', x, v[0], v[1], v[0]*pow(2.0, v[1]) );
}
```
* * *
## C APIs
### Usage
```c
#include "stdlib/number/float32/base/normalize.h"
```
#### stdlib_base_float32_normalize( x, \*y, \*exp )
Returns a normal number `y` and exponent `exp` satisfying `x = y * 2^exp`.
```c
#include
float y;
int32_t exp;
stdlib_base_float32_normalize( 3.14, &y, &exp );
```
The function accepts the following arguments:
- **x**: `[in] float` input value.
- **y**: `[out] float*` destination for normal number.
- **exp**: `[out] int32_t*` destination for exponent.
```c
void stdlib_base_float32_normalize( const float x, float *y, int32_t *exp );
```
### Examples
```c
#include "stdlib/number/float32/base/normalize.h"
#include
#include
int main( void ) {
float x[] = { 4.0f, 0.0f, -0.0f, 1.0f, -1.0f, 3.14f, -3.14f, 1.0e-38f, -1.0e-38f, 1.0f/0.0f, -1.0f/0.0f, 0.0f/0.0f };
int32_t exp;
float y;
int i;
for ( i = 0; i < 12; i++ ) {
stdlib_base_float32_normalize( x[ i ], &y, &exp );
printf( "%f => y: %f, exp: %" PRId32 "\n", x[ i ], y, exp );
}
}
```
[ieee754]: https://en.wikipedia.org/wiki/IEEE_754-1985
[@stdlib/number/float64/base/normalize]: https://github.com/stdlib-js/number/tree/main/float64/base/normalize