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real

Return the real component of a double-precision complex floating-point number.

Installation

npm install @stdlib/complex-float64-real

Alternatively,

• To load the package in a website via a script tag without installation and bundlers, use the ES Module available on the esm branch (see README).
• If you are using Deno, visit the deno branch (see README for usage intructions).
• For use in Observable, or in browser/node environments, use the Universal Module Definition (UMD) build available on the umd branch (see README).

The branches.md file summarizes the available branches and displays a diagram illustrating their relationships.

To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.

Usage

var real = require( '@stdlib/complex-float64-real' );

real( z )

Returns the real component of a double-precision complex floating-point number.

var Complex128 = require( '@stdlib/complex-float64-ctor' );

var z = new Complex128( 5.0, 3.0 );
var re = real( z );
// returns 5.0

Examples

var Complex128 = require( '@stdlib/complex-float64-ctor' );
var discreteUniform = require( '@stdlib/random-base-discrete-uniform' );
var filledarrayBy = require( '@stdlib/array-filled-by' );
var real = require( '@stdlib/complex-float64-real' );

function random() {
    return new Complex128( discreteUniform( -10, 10 ), discreteUniform( -10, 10 ) ); // eslint-disable-line max-len
}

// Generate an array of random complex numbers:
var x = filledarrayBy( 100, 'complex128', random );
// returns <Complex128Array>

// Retrieve the real component of each complex number...
var z;
var i;
for ( i = 0; i < x.length; i++ ) {
    z = x.get( i );
    console.log( 'real(%s) = %d', z.toString(), real( z ) );
}

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C APIs

Usage

#include "stdlib/complex/float64/real.h"

stdlib_complex128_real( z )

Returns the real component of a double-precision complex floating-point number.

#include "stdlib/complex/float64/ctor.h"

stdlib_complex128_t z = stdlib_complex128( 5.0, 2.0 );

// ...

double re = stdlib_complex128_real( z );
// returns 5.0

The function accepts the following arguments:

• z: [in] stdlib_complex128_t double-precision complex floating-point number.

double stdlib_complex128_real( const stdlib_complex128_t z );

Examples

#include "stdlib/complex/float64/real.h"
#include "stdlib/complex/float64/ctor.h"
#include <stdio.h>

int main( void ) {
    const stdlib_complex128_t x[] = {
        stdlib_complex128( 5.0, 2.0 ),
        stdlib_complex128( -2.0, 1.0 ),
        stdlib_complex128( 0.0, -0.0 ),
        stdlib_complex128( 0.0/0.0, 0.0/0.0 )
    };

    int i;
    for ( i = 0; i < 4; i++ ) {
        printf( "real(v) = %lf\n", stdlib_complex128_real( x[ i ] ) );
    }
}

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See Also

• @stdlib/complex-float64/imag: return the imaginary component of a double-precision complex floating-point number.
• @stdlib/complex-float64/reim: return the real and imaginary components of a double-precision complex 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.