Numbers

Tracking range

Trackers.number keeps track of the minimum, maximum and average of a stream of numbers, without storing them.


import { Trackers } from 'https://unpkg.com/ixfx/dist/bundle.js';

// Initialise
const t = Trackers.number();

// Add some random values
for (let i=0;i<10;i++) t.seen(Math.floor(Math.random()*100)));

// Get computed values
t.avg   // eg. 25.3
t.min   // eg. 2
t.total // eg. 534

An example usage might be to track the range of a sensor over time. The pointer scale demo (source) uses numberTracker and pointsTracker.

Counting

Numbers.count is a generator that produces integer values from zero.


import { count } from 'https://unpkg.com/ixfx/dist/numbers.js';
let str = ``;
for (const v of count(5)) {
  v += v + ' ';
} // v: "0 1 2 3 4 "

// Or:
const values = [...count(5)]; // [0,1,2,3,4]

Numbers.count is useful because the code is more readable than using a for loop to increment, and it cuts down on likely errors.

Values within a range

Numbers.numericRange generates values in a range by a given step amount (much like a classic for loop).


import { numericRange } from 'https://unpkg.com/ixfx/dist/numbers.js';

// Count from 0..1 by steps of 0.1
let loopForever = numericRange(0.1, 0, 1);
for (v of loopForever) {
 console.log(v);
}

Computations

Arrays.minMaxAvg might also be a useful when working with arrays. It returns the minimum, maximum, average and total.


import { Arrays } from 'https://unpkg.com/ixfx/dist/data.js';

const mma = Arrays.minMaxAvg([100,20,0,50]); // { total:170, max:100, min:0, avg:42.5 }