About stdlib...

We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.

The library is fully decomposable, being architected in such a way that you can swap out and mix and match APIs and functionality to cater to your exact preferences and use cases.

When you use stdlib, you can be absolutely certain that you are using the most thorough, rigorous, well-written, studied, documented, tested, measured, and high-quality code out there.

To join us in bringing numerical computing to the web, get started by checking us out on GitHub, and please consider financially supporting stdlib. We greatly appreciate your continued support!

cidentity

Evaluate the identity function of a double-precision complex floating-point number.

The identity-function is defined as

$$f(z) = z$$

for all z.

Usage

import cidentity from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-base-identity@deno/mod.js';

cidentity( z )

Evaluates the identity function for a double-precision complex floating-point number.

import Complex128 from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-ctor@deno/mod.js';
import real from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-real@deno/mod.js';
import imag from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-imag@deno/mod.js';

var v = cidentity( new Complex128( -1.0, 2.0 ) );
// returns <Complex128>

var re = real( v );
// returns -1.0

var im = imag( v );
// returns 2.0

Examples

import discreteUniform from 'https://cdn.jsdelivr.net/gh/stdlib-js/random-base-discrete-uniform@deno/mod.js';
import Complex128 from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-ctor@deno/mod.js';
import cidentity from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-base-identity@deno/mod.js';

var z;
var i;
for ( i = 0; i < 100; i++ ) {
    z = new Complex128( discreteUniform( -50, 50 ), discreteUniform( -50, 50 ) );
    console.log( 'identity(%s) = %s', z, cidentity( z ) );
}

---

See Also

• @stdlib/complex-float32/base/identity: evaluate the identity function for a single-precision complex floating-point number.
• @stdlib/number-float64/base/identity: evaluate the identity function for a double-precision floating-point number.

---

Notice

This package is part of stdlib, a standard library 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 © 2016-2025. The Stdlib Authors.