Generate a frequency table.
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> Generate a frequency table.
``bash`
npm install @stdlib/utils-tabulate
`javascript`
var tabulate = require( '@stdlib/utils-tabulate' );
#### tabulate( collection )
Generates a frequency table.
`javascript
var arr = [ 'beep', 'boop', 'foo', 'beep' ];
var out = tabulate( arr );
// returns [ [ 'beep', 2, 0.5 ], [ 'boop', 1, 0.25 ], [ 'foo', 1, 0.25 ] ]
`
The returned frequency table is an array of arrays. Each sub-array corresponds to a unique value in the input collection and is structured as follows:
- 0: unique value.1
- : value count.2
- : frequency percentage.
- A collection may be either an [Array][mdn-array], [Typed Array][mdn-typed-array], or an array-like [Object][mdn-object] (excluding strings and functions).
`javascript
var randu = require( '@stdlib/random-base-randu' );
var floor = require( '@stdlib/math-base-special-floor' );
var tabulate = require( '@stdlib/utils-tabulate' );
var vals;
var arr;
var out;
var i;
var j;
vals = [ 'beep', 'boop', 'foo', 'bar', 'woot', 'woot' ];
// Generate a random collection...
arr = new Array( 100 );
for ( i = 0; i < arr.length; i++ ) {
j = floor( randu()*vals.length );
arr[ i ] = vals[ j ];
}
// Generate a frequency table:
out = tabulate( arr );
console.log( out );
`
*
- [@stdlib/utils-count-by][@stdlib/utils/count-by]: group values according to an indicator function and return group counts.
- [@stdlib/utils-group-by][@stdlib/utils/group-by]: group values according to an indicator function.
- [@stdlib/utils-tabulate-by][@stdlib/utils/tabulate-by]: generate a frequency table according to an indicator function.
*
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].
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---
See [LICENSE][stdlib-license].
Copyright © 2016-2026. The Stdlib [Authors][stdlib-authors].
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[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/utils-tabulate/tree/deno
[deno-readme]: https://github.com/stdlib-js/utils-tabulate/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/utils-tabulate/tree/umd
[umd-readme]: https://github.com/stdlib-js/utils-tabulate/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/utils-tabulate/tree/esm
[esm-readme]: https://github.com/stdlib-js/utils-tabulate/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/utils-tabulate/blob/main/branches.md
[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/utils-tabulate/main/LICENSE
[mdn-array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array
[mdn-typed-array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray
[mdn-object]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object
[@stdlib/utils/count-by]: https://www.npmjs.com/package/@stdlib/utils-count-by
[@stdlib/utils/group-by]: https://www.npmjs.com/package/@stdlib/utils-group-by
[@stdlib/utils/tabulate-by]: https://www.npmjs.com/package/@stdlib/utils-tabulate-by