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exponent
Return an integer corresponding to the unbiased exponent of a double-precision floating-point number.
Installation
npm install @stdlib/number-float64-base-exponentUsage
var exponent = require( '@stdlib/number-float64-base-exponent' );exponent( x )
Returns an integer corresponding to the unbiased exponent of a double-precision floating-point number.
var exp = exponent( 3.14e307 ); // => 2**1021 ~ 1e307
// returns 1021
exp = exponent( 3.14e-307 ); // => 2**-1019 ~ 1e-307
// returns -1019
exp = exponent( -3.14 );
// returns 1
exp = exponent( 0.0 );
// returns -1023
exp = exponent( NaN );
// returns 1024Examples
var randu = require( '@stdlib/random-base-uniform' );
var discreteUniform = require( '@stdlib/random-base-discrete-uniform' );
var pow = require( '@stdlib/math-base-special-pow' );
var exponent = require( '@stdlib/number-float64-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( 0.0, 10.0 );
exp = discreteUniform( -323, 323 );
x = frac * pow( 10.0, exp );
e = exponent( x );
console.log( 'x: %d. unbiased exponent: %d.', x, e );
}C APIs
Usage
#include "stdlib/number/float64/base/exponent.h"stdlib_base_float64_exponent( x )
Returns an integer corresponding to the unbiased exponent of a double-precision floating-point number.
#include <stdint.h>
int32_t out = stdlib_base_float64_exponent( 3.14 );The function accepts the following arguments:
-
x:
[in] doubleinput value.
int32_t stdlib_base_float64_exponent( const double x );Examples
#include "stdlib/number/float64/base/exponent.h"
#include <stdint.h>
#include <stdio.h>
#include <inttypes.h>
int main( void ) {
double x[] = { 4.0, 0.0, -0.0, 1.0, -1.0, 3.14, -3.14, 1.0e308, -1.0e308, 1.0/0.0, -1.0/0.0, 0.0/0.0 };
int32_t out;
int i;
for ( i = 0; i < 12; i++ ) {
out = stdlib_base_float64_exponent( x[ i ] );
printf( "%lf => out: %" PRId32 "\n", x[ i ], out );
}
}See Also
-
@stdlib/number-float32/base/exponent: return an integer corresponding to the unbiased exponent of a single-precision floating-point number.
Notice
This package is part of 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, see the main project repository.
Community
License
See LICENSE.
Copyright
Copyright © 2016-2024. The Stdlib Authors.