time-to-botec/js/node_modules/@stdlib/utils/tabulate/README.md

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@license Apache-2.0
Copyright (c) 2018 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.
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# tabulate
> Generate a frequency table.
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## Usage
```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
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## Notes
- 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`).
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## Examples
<!-- eslint no-undef: "error" -->
```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 );
```
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[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
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