Return a normal number `y` and exponent `exp` satisfying `x = y * 2^exp`.
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> Return a normal number y and exponent exp satisfying x = y * 2^exp.
``bash`
npm install @stdlib/number-float64-base-normalize
`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
var bool = ( v === out );
// returns true
`
`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]) );
}
`
*
`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
double y;
int32_t exp;
stdlib_base_float64_normalize( 3.14, &y, &exp );
`
The function accepts the following arguments:
- x: [in] double input value.[out] double*
- y: destination for normal number.[out] int32_t*
- exp: destination for exponent.
`c`
void stdlib_base_float64_normalize( const double x, double y, int32_t exp );
`c
#include "stdlib/number/float64/base/normalize.h"
#include
#include
#include
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 );
}
}
`
*
- [@stdlib/number-float32/base/normalize][@stdlib/number/float32/base/normalize]: return a normal number y and exponent exp satisfying x = y * 2^exp.
*
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].
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---
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