npm package: @stdlib/stats-base-ztest-two-sample-results-float64
Description: Create a two-sample Z-test double-precision floating-point results object.
Author: The Stdlib Authors
Latest version: 0.0.1

<!--

@license Apache-2.0

Copyright (c) 2025 The Stdlib Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

-->


<details>
  <summary>
    About stdlib...
  </summary>
  <p>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.</p>
  <p>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.</p>
  <p>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.</p>
  <p>To join us in bringing numerical computing to the web, get started by checking us out on <a href="https://github.com/stdlib-js/stdlib">GitHub</a>, and please consider <a href="https://opencollective.com/stdlib">financially supporting stdlib</a>. We greatly appreciate your continued support!</p>
</details>

# Float64Results

[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url] <!-- [![dependencies][dependencies-image]][dependencies-url] -->

> Create a two-sample Z-test double-precision floating-point results object.

<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->

<section class="intro">

</section>

<!-- /.intro -->

<!-- Package usage documentation. -->

<section class="installation">

## Installation

```bash
npm install @stdlib/stats-base-ztest-two-sample-results-float64
```

</section>

<section class="usage">

## Usage

```javascript
var Float64Results = require( '@stdlib/stats-base-ztest-two-sample-results-float64' );
```

#### Float64Results( \[arg\[, byteOffset\[, byteLength]]] )

Returns a two-sample Z-test double-precision floating-point results object.

```javascript
var results = new Float64Results();
// returns {...}
```

The function supports the following parameters:

-   **arg**: an [`ArrayBuffer`][@stdlib/array/buffer] or a data object (_optional_).
-   **byteOffset**: byte offset (_optional_).
-   **byteLength**: maximum byte length (_optional_).

A data object argument is an object having one or more of the following properties:

-   **rejected**: boolean indicating whether the null hypothesis was rejected.
-   **alternative**: the alternative hypothesis (e.g., `'two-sided'`, `'less'`, or `'greater'`).
-   **alpha**: significance level.
-   **pValue**: p-value.
-   **statistic**: test statistic.
-   **ci**: confidence interval as a [`Float64Array`][@stdlib/array/float64].
-   **nullValue**: difference in means under the null hypothesis.
-   **xmean**: sample mean of `x`.
-   **ymean**: sample mean of `y`.

#### Float64Results.prototype.rejected

Boolean indicating whether the null hypothesis was rejected.

```javascript
var results = new Float64Results();
// returns {...}

// ...

var v = results.rejected;
// returns <boolean>
```

#### Float64Results.prototype.alternative

The alternative hypothesis.

```javascript
var results = new Float64Results();
// returns {...}

// ...

var v = results.alternative;
// returns <string>
```

#### Float64Results.prototype.alpha

Significance level.

```javascript
var results = new Float64Results();
// returns {...}

// ...

var v = results.alpha;
// returns <number>
```

#### Float64Results.prototype.pValue

The test p-value.

```javascript
var results = new Float64Results();
// returns {...}

// ...

var v = results.pValue;
// returns <number>
```

#### Float64Results.prototype.statistic

The test statistic.

```javascript
var results = new Float64Results();
// returns {...}

// ...

var v = results.statistic;
// returns <number>
```

#### Float64Results.prototype.ci

Confidence interval.

```javascript
var results = new Float64Results();
// returns {...}

// ...

var v = results.ci;
// returns <Float64Array>
```

#### Float64Results.prototype.nullValue

Difference in means under the null hypothesis.

```javascript
var results = new Float64Results();
// returns {...}

// ...

var v = results.nullValue;
// returns <number>
```

#### Float64Results.prototype.xmean

Sample mean of `x`.

```javascript
var results = new Float64Results();
// returns {...}

// ...

var v = results.xmean;
// returns <number>
```

#### Float64Results.prototype.ymean

Sample mean of `y`.

```javascript
var results = new Float64Results();
// returns {...}

// ...

var v = results.ymean;
// returns <number>
```

#### Float64Results.prototype.toString( \[options] )

Serializes a results object to a formatted string.

```javascript
var results = new Float64Results();
// returns {...}

// ...

var v = results.toString();
// returns <string>
```

The method supports the following options:

-   **digits**: number of digits to display after decimal points. Default: `4`.
-   **decision**: boolean indicating whether to show the test decision. Default: `true`.

Example output:

```text

Two-sample Z-test

Alternative hypothesis: True difference in means is less than 1.0

    pValue: 0.0406
    statistic: 9.9901
    95% confidence interval: [9.7821, 10.4451]

Test Decision: Reject null in favor of alternative at 5% significance level

```

#### Float64Results.prototype.toJSON( \[options] )

Serializes a results object as a JSON object.

```javascript
var results = new Float64Results();
// returns {...}

// ...

var v = results.toJSON();
// returns {...}
```

`JSON.stringify()` implicitly calls this method when stringifying a results instance.

#### Float64Results.prototype.toDataView()

Returns a [`DataView`][@stdlib/array/dataview] of a results object.

```javascript
var results = new Float64Results();
// returns {...}

// ...

var v = results.toDataView();
// returns <DataView>
```

</section>

<!-- /.usage -->

<!-- Package usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="notes">

## Notes

-   A results object is a [`struct`][@stdlib/dstructs/struct] providing a fixed-width composite data structure for storing two-sample Z-test results and providing an ABI-stable data layout for JavaScript-C interoperation.

</section>

<!-- /.notes -->

<!-- Package usage examples. -->

<section class="examples">

## Examples

<!-- eslint no-undef: "error" -->

```javascript
var Float64Array = require( '@stdlib/array-float64' );
var Results = require( '@stdlib/stats-base-ztest-two-sample-results-float64' );

var results = new Results({
    'rejected': true,
    'alpha': 0.05,
    'pValue': 0.0132,
    'statistic': 2.4773,
    'nullValue': 0.0,
    'xmean': 3.7561,
    'ymean': 3.0129,
    'ci': new Float64Array( [ 9.9983, 11.4123 ] ),
    'alternative': 'two-sided'
});

var str = results.toString({
    'format': 'linear'
});
console.log( str );
```

</section>

<!-- /.examples -->

<!-- C interface documentation. -->

* * *

<section class="c">

## C APIs

<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->

<section class="intro">

</section>

<!-- /.intro -->

<!-- C usage documentation. -->

<section class="usage">

### Usage

```c
#include "stdlib/stats/base/ztest/two-sample/results/float64.h"
```

#### stdlib_stats_ztest_two_sample_float64_results

Structure for holding double-precision floating-point test results.

```c
#include <stdbool.h>
#include <stdint.h>

struct stdlib_stats_ztest_two_sample_float64_results {
    // Boolean indicating whether the null hypothesis was rejected:
    bool rejected;

    // Alternative hypothesis:
    int8_t alternative;

    // Significance level:
    double alpha;

    // p-value:
    double pValue;

    // Test statistic:
    double statistic;

    // Confidence interval:
    double ci[ 2 ];

    // Difference in means under the null hypothesis:
    double nullValue;

    // Sample mean of `x`:
    double xmean;

    // Sample mean of `y`:
    double ymean;
};
```

</section>

<!-- /.usage -->

<!-- C API usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="notes">

</section>

<!-- /.notes -->

<!-- C API usage examples. -->

<section class="examples">

</section>

<!-- /.examples -->

</section>

<!-- /.c -->

<!-- Section to include cited references. If references are included, add a horizontal rule *before* the section. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="references">

</section>

<!-- /.references -->

<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

</section>

<!-- /.related -->

<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->


<section class="main-repo" >

* * *

## Notice

This package is part of [stdlib][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][stdlib], see the main project [repository][stdlib].

#### Community

[![Chat][chat-image]][chat-url]

---

## License

See [LICENSE][stdlib-license].


## Copyright

Copyright &copy; 2016-2026. The Stdlib [Authors][stdlib-authors].

</section>

<!-- /.stdlib -->

<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="links">

[npm-image]: http://img.shields.io/npm/v/@stdlib/stats-base-ztest-two-sample-results-float64.svg
[npm-url]: https://npmjs.org/package/@stdlib/stats-base-ztest-two-sample-results-float64

[test-image]: https://github.com/stdlib-js/stats-base-ztest-two-sample-results-float64/actions/workflows/test.yml/badge.svg?branch=v0.0.1
[test-url]: https://github.com/stdlib-js/stats-base-ztest-two-sample-results-float64/actions/workflows/test.yml?query=branch:v0.0.1

[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/stats-base-ztest-two-sample-results-float64/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/stats-base-ztest-two-sample-results-float64?branch=main

<!--

[dependencies-image]: https://img.shields.io/david/stdlib-js/stats-base-ztest-two-sample-results-float64.svg
[dependencies-url]: https://david-dm.org/stdlib-js/stats-base-ztest-two-sample-results-float64/main

-->

[chat-image]: https://img.shields.io/badge/zulip-join_chat-brightgreen.svg
[chat-url]: https://stdlib.zulipchat.com

[stdlib]: https://github.com/stdlib-js/stdlib

[stdlib-authors]: https://github.com/stdlib-js/stdlib/graphs/contributors

[umd]: https://github.com/umdjs/umd
[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules

[deno-url]: https://github.com/stdlib-js/stats-base-ztest-two-sample-results-float64/tree/deno
[deno-readme]: https://github.com/stdlib-js/stats-base-ztest-two-sample-results-float64/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/stats-base-ztest-two-sample-results-float64/tree/umd
[umd-readme]: https://github.com/stdlib-js/stats-base-ztest-two-sample-results-float64/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/stats-base-ztest-two-sample-results-float64/tree/esm
[esm-readme]: https://github.com/stdlib-js/stats-base-ztest-two-sample-results-float64/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/stats-base-ztest-two-sample-results-float64/blob/main/branches.md

[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/stats-base-ztest-two-sample-results-float64/main/LICENSE

[@stdlib/dstructs/struct]: https://www.npmjs.com/package/@stdlib/dstructs-struct

[@stdlib/array/dataview]: https://www.npmjs.com/package/@stdlib/array-dataview

[@stdlib/array/float64]: https://www.npmjs.com/package/@stdlib/array-float64

[@stdlib/array/buffer]: https://www.npmjs.com/package/@stdlib/array-buffer

</section>

<!-- /.links -->