@stdlib/number-float64-base-exponent

What is @stdlib/number-float64-base-exponent?

@stdlib/number-float64-base-exponent is a package that provides functionality to extract the exponent from a double-precision floating-point number (float64). This can be useful in various numerical computations where understanding the exponent part of a floating-point number is necessary.

What are @stdlib/number-float64-base-exponent's main functionalities?

Extract Exponent

This feature allows you to extract the exponent from a given double-precision floating-point number. In this example, the exponent of 4.0 is extracted, which is 2.

const exponent = require('@stdlib/number-float64-base-exponent');
const exp = exponent(4.0); // returns 2

Other packages similar to @stdlib/number-float64-base-exponent

math-float64-exponent

The math-float64-exponent package provides similar functionality to extract the exponent from a float64 number. It is comparable to @stdlib/number-float64-base-exponent in terms of functionality but may differ in implementation details and additional features.

README

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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-exponent

Usage

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 1024

Examples

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 );
}

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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] double input 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 );
    }
}

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See Also

• @stdlib/number-float32/base/exponent: return an integer corresponding to the unbiased exponent of a single-precision floating-point number.

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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

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License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.