@stdlib/utils
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Standard utilities.
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{{alias}}( collection, [options,] indicator )
Generates a frequency table according to an indicator function.
When invoked, the indicator function is provided two arguments:
- value: collection value.
- index: collection index.
The table is an array of arrays where each sub-array corresponds to a unique
value in the input collection. Each sub-array is structured as follows:
- 0: unique value.
- 1: value count.
- 2: frequency percentage.
If provided an empty collection, the function returns an empty array.
Parameters
----------
collection: Array|TypedArray|Object
Input collection to tabulate. If provided an object, the object must be
array-like (excluding strings and functions).
options: Object (optional)
Options.
options.thisArg: any (optional)
Execution context.
indicator: Function
Indicator function specifying how to categorize a collection element.
Returns
-------
out: Array<Array>|Array
Frequency table.
Examples
--------
> function indicator( value ) { return value[ 0 ]; };
> var collection = [ 'beep', 'boop', 'foo', 'beep' ];
> var out = {{alias}}( collection, indicator )
[ [ 'b', 3, 0.75 ], [ 'f', 1, 0.25 ] ]
See Also
--------