Return an integer corresponding to the unbiased exponent of a single-precision floating-point number.
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Return an integer corresponding to the unbiased exponent of a [single-precision floating-point number][ieee754].
bash
npm install @stdlib/number-float32-base-exponentscript tag without installation and bundlers, use the [ES Module][es-module] available on the [esm][esm-url] branch (see [README][esm-readme]).deno][deno-url] branch (see [README][deno-readme] for usage intructions).umd][umd-url] branch (see [README][umd-readme]).javascript
var exponentf = require( '@stdlib/number-float32-base-exponent' );javascript
var toFloat32 = require( '@stdlib/number-float64-base-to-float32' );
var exp = exponentf( toFloat32( 3.14e34 ) ); // => 2^114 ~ 2.08e34
// returns 114
exp = exponentf( toFloat32( 3.14e-34 ) ); // => 2^-112 ~ 1.93e-34
// returns -112
exp = exponentf( toFloat32( -3.14 ) );
// returns 1
exp = exponentf( 0.0 );
// returns -127
exp = exponentf( NaN );
// returns 128javascript
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 exponentf = require( '@stdlib/number-float32-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()*44.0 ) - 22;
x = frac * pow( 10.0, exp );
x = toFloat32( x );
e = exponentf( x );
console.log( 'x: %d. unbiased exponent: %d.', x, e );
}c
#include "stdlib/number/float32/base/exponent.h"c
#include <stdint.h>
int32_t out = stdlib_base_float32_exponent( 3.14f );[in] float input value.c
int32_t stdlib_base_float32_exponent( const float x );c
#include "stdlib/number/float32/base/exponent.h"
#include <stdint.h>
#include <stdio.h>
#include <inttypes.h>
int main( void ) {
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 };
int32_t out;
int i;
for ( i = 0; i < 12; i++ ) {
out = stdlib_base_float32_exponent( x[ i ] );
printf( "%f => out: %" PRId32 "\n", x[ i ], out );
}
}
