isAlmostSameValue

Test whether two double-precision complex floating-point numbers are approximately the same value within a specified number of ULPs (units in the last place).

Installation

npm install @stdlib/complex-float64-base-assert-is-almost-same-value

Usage

var isAlmostSameValue = require( '@stdlib/complex-float64-base-assert-is-almost-same-value' );

isAlmostSameValue( z1, z2, maxULP )

Tests whether two double-precision complex floating-point numbers are approximately the same value within a specified number of ULPs (units in the last place).

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

var z1 = new Complex128( 1.0, 3.0 );
var z2 = new Complex128( 1.0+EPS, 3.0 );

var out = isAlmostSameValue( z1, z2, 0 );
// returns false

out = isAlmostSameValue( z1, z2, 1 );
// returns true

In contrast to the strict equality operator ===, the function distinguishes between +0 and -0 and treats NaNs as the same value.

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

var z1 = new Complex128( NaN, 3.0 );
var z2 = new Complex128( 1.0, 3.0 );

var out = isAlmostSameValue( z1, z2, 1 );
// returns false

out = isAlmostSameValue( z2, z1, 1 );
// returns false

z1 = new Complex128( NaN, NaN );
z2 = new Complex128( NaN, NaN );

out = isAlmostSameValue( z1, z2, 1 );
// returns true

z1 = new Complex128( 0.0, 0.0 );
z2 = new Complex128( -0.0, -0.0 );

out = isAlmostSameValue( z1, z2, 0 );
// returns false

Notes

• The function implements the SameValue Algorithm as specified in ECMAScript 5.

Examples

var EPS = require( '@stdlib/constants-float64-eps' );
var Complex128 = require( '@stdlib/complex-float64-ctor' );
var isAlmostSameValue = require( '@stdlib/complex-float64-base-assert-is-almost-same-value' );

var z1 = new Complex128( 1.0, 3.0+EPS );
var z2 = new Complex128( 1.0+EPS, 3.0 );
console.log( isAlmostSameValue( z1, z2, 1 ) );
// => true

z1 = new Complex128( 1.0, 3.0+EPS );
z2 = new Complex128( 1.0+EPS+EPS, 3.0 );
console.log( isAlmostSameValue( z1, z2, 1 ) );
// => false

z1 = new Complex128( 0.0, 0.0 );
z2 = new Complex128( -0.0, 0.0 );
console.log( isAlmostSameValue( z1, z2, 0 ) );
// => false

z1 = new Complex128( NaN, 0.0 );
z2 = new Complex128( 1.0, 0.0 );
console.log( isAlmostSameValue( z1, z2, 1 ) );
// => false

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 © 2016-2026. The Stdlib Authors.