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https://github.com/stdlib-js/blas-ext-base-ssumkbn
Calculate the sum of single-precision floating-point strided array elements using an improved Kahan–Babuška algorithm.
https://github.com/stdlib-js/blas-ext-base-ssumkbn
blas compensated extended javascript kahan kbn math mathematics node node-js nodejs statistics stats stdlib strided strided-array sum summation total typed
Last synced: about 21 hours ago
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Calculate the sum of single-precision floating-point strided array elements using an improved Kahan–Babuška algorithm.
- Host: GitHub
- URL: https://github.com/stdlib-js/blas-ext-base-ssumkbn
- Owner: stdlib-js
- License: apache-2.0
- Created: 2021-06-15T17:56:21.000Z (over 3 years ago)
- Default Branch: main
- Last Pushed: 2024-11-01T09:51:05.000Z (14 days ago)
- Last Synced: 2024-11-09T12:06:10.699Z (6 days ago)
- Topics: blas, compensated, extended, javascript, kahan, kbn, math, mathematics, node, node-js, nodejs, statistics, stats, stdlib, strided, strided-array, sum, summation, total, typed
- Language: JavaScript
- Homepage:
- Size: 628 KB
- Stars: 1
- Watchers: 3
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
- Code of conduct: CODE_OF_CONDUCT.md
- Citation: CITATION.cff
- Security: SECURITY.md
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README
About stdlib...
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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!
# ssumkbn
[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url]
> Calculate the sum of single-precision floating-point strided array elements using an improved Kahan–Babuška algorithm.
## Installation
```bash
npm install @stdlib/blas-ext-base-ssumkbn
```
Alternatively,
- To load the package in a website via a `script` tag without installation and bundlers, use the [ES Module][es-module] available on the [`esm`][esm-url] branch (see [README][esm-readme]).
- If you are using Deno, visit the [`deno`][deno-url] branch (see [README][deno-readme] for usage intructions).
- For use in Observable, or in browser/node environments, use the [Universal Module Definition (UMD)][umd] build available on the [`umd`][umd-url] branch (see [README][umd-readme]).
The [branches.md][branches-url] 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
```javascript
var ssumkbn = require( '@stdlib/blas-ext-base-ssumkbn' );
```
#### ssumkbn( N, x, stride )
Computes the sum of single-precision floating-point strided array elements using an improved Kahan–Babuška algorithm.
```javascript
var Float32Array = require( '@stdlib/array-float32' );
var x = new Float32Array( [ 1.0, -2.0, 2.0 ] );
var N = x.length;
var v = ssumkbn( N, x, 1 );
// returns 1.0
```
The function has the following parameters:
- **N**: number of indexed elements.
- **x**: input [`Float32Array`][@stdlib/array/float32].
- **stride**: index increment for `x`.
The `N` and `stride` parameters determine which elements in the strided array are accessed at runtime. For example, to compute the sum of every other element in the strided array,
```javascript
var Float32Array = require( '@stdlib/array-float32' );
var x = new Float32Array( [ 1.0, 2.0, 2.0, -7.0, -2.0, 3.0, 4.0, 2.0 ] );
var v = ssumkbn( 4, x, 2 );
// returns 5.0
```
Note that indexing is relative to the first index. To introduce an offset, use [`typed array`][mdn-typed-array] views.
```javascript
var Float32Array = require( '@stdlib/array-float32' );
var x0 = new Float32Array( [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0 ] );
var x1 = new Float32Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element
var v = ssumkbn( 4, x1, 2 );
// returns 5.0
```
#### ssumkbn.ndarray( N, x, stride, offset )
Computes the sum of single-precision floating-point strided array elements using an improved Kahan–Babuška algorithm and alternative indexing semantics.
```javascript
var Float32Array = require( '@stdlib/array-float32' );
var x = new Float32Array( [ 1.0, -2.0, 2.0 ] );
var N = x.length;
var v = ssumkbn.ndarray( N, x, 1, 0 );
// returns 1.0
```
The function has the following additional parameters:
- **offset**: starting index for `x`.
While [`typed array`][mdn-typed-array] views mandate a view offset based on the underlying `buffer`, the `offset` parameter supports indexing semantics based on a starting index. For example, to calculate the sum of every other value in the strided array starting from the second value
```javascript
var Float32Array = require( '@stdlib/array-float32' );
var x = new Float32Array( [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0 ] );
var v = ssumkbn.ndarray( 4, x, 2, 1 );
// returns 5.0
```
## Notes
- If `N <= 0`, both functions return `0.0`.
## Examples
```javascript
var discreteUniform = require( '@stdlib/random-base-discrete-uniform' ).factory;
var filledarrayBy = require( '@stdlib/array-filled-by' );
var ssumkbn = require( '@stdlib/blas-ext-base-ssumkbn' );
var x = filledarrayBy( 10, 'float32', discreteUniform( 0, 100 ) );
console.log( x );
var v = ssumkbn( x.length, x, 1 );
console.log( v );
```
* * *
## References
- Neumaier, Arnold. 1974. "Rounding Error Analysis of Some Methods for Summing Finite Sums." _Zeitschrift Für Angewandte Mathematik Und Mechanik_ 54 (1): 39–51. doi:[10.1002/zamm.19740540106][@neumaier:1974a].
* * *
## See Also
- [`@stdlib/blas-ext/base/dsumkbn`][@stdlib/blas/ext/base/dsumkbn]: calculate the sum of double-precision floating-point strided array elements using an improved Kahan–Babuška algorithm.
- [`@stdlib/blas-ext/base/gsumkbn`][@stdlib/blas/ext/base/gsumkbn]: calculate the sum of strided array elements using an improved Kahan–Babuška algorithm.
- [`@stdlib/blas-ext/base/snansumkbn`][@stdlib/blas/ext/base/snansumkbn]: calculate the sum of single-precision floating-point strided array elements, ignoring NaN values and using an improved Kahan–Babuška algorithm.
- [`@stdlib/blas-ext/base/ssum`][@stdlib/blas/ext/base/ssum]: calculate the sum of single-precision floating-point strided array elements.
- [`@stdlib/blas-ext/base/ssumkbn2`][@stdlib/blas/ext/base/ssumkbn2]: calculate the sum of single-precision floating-point strided array elements using a second-order iterative Kahan–Babuška algorithm.
- [`@stdlib/blas-ext/base/ssumors`][@stdlib/blas/ext/base/ssumors]: calculate the sum of single-precision floating-point strided array elements using ordinary recursive summation.
- [`@stdlib/blas-ext/base/ssumpw`][@stdlib/blas/ext/base/ssumpw]: calculate the sum of single-precision floating-point strided array elements using pairwise summation.
* * *
## 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 © 2016-2024. The Stdlib [Authors][stdlib-authors].
[npm-image]: http://img.shields.io/npm/v/@stdlib/blas-ext-base-ssumkbn.svg
[npm-url]: https://npmjs.org/package/@stdlib/blas-ext-base-ssumkbn
[test-image]: https://github.com/stdlib-js/blas-ext-base-ssumkbn/actions/workflows/test.yml/badge.svg?branch=main
[test-url]: https://github.com/stdlib-js/blas-ext-base-ssumkbn/actions/workflows/test.yml?query=branch:main
[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/blas-ext-base-ssumkbn/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/blas-ext-base-ssumkbn?branch=main
[chat-image]: https://img.shields.io/gitter/room/stdlib-js/stdlib.svg
[chat-url]: https://app.gitter.im/#/room/#stdlib-js_stdlib:gitter.im
[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/blas-ext-base-ssumkbn/tree/deno
[deno-readme]: https://github.com/stdlib-js/blas-ext-base-ssumkbn/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/blas-ext-base-ssumkbn/tree/umd
[umd-readme]: https://github.com/stdlib-js/blas-ext-base-ssumkbn/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/blas-ext-base-ssumkbn/tree/esm
[esm-readme]: https://github.com/stdlib-js/blas-ext-base-ssumkbn/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/blas-ext-base-ssumkbn/blob/main/branches.md
[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/blas-ext-base-ssumkbn/main/LICENSE
[@stdlib/array/float32]: https://github.com/stdlib-js/array-float32
[mdn-typed-array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray
[@neumaier:1974a]: https://doi.org/10.1002/zamm.19740540106
[@stdlib/blas/ext/base/dsumkbn]: https://github.com/stdlib-js/blas-ext-base-dsumkbn
[@stdlib/blas/ext/base/gsumkbn]: https://github.com/stdlib-js/blas-ext-base-gsumkbn
[@stdlib/blas/ext/base/snansumkbn]: https://github.com/stdlib-js/blas-ext-base-snansumkbn
[@stdlib/blas/ext/base/ssum]: https://github.com/stdlib-js/blas-ext-base-ssum
[@stdlib/blas/ext/base/ssumkbn2]: https://github.com/stdlib-js/blas-ext-base-ssumkbn2
[@stdlib/blas/ext/base/ssumors]: https://github.com/stdlib-js/blas-ext-base-ssumors
[@stdlib/blas/ext/base/ssumpw]: https://github.com/stdlib-js/blas-ext-base-ssumpw