JarCastingGiven an array of timeseries data ordered from oldest to newest, aggregate the sum or average of values inside X periods of Y milliseconds each, ending at the date given.
Series data is expected to be an array of objects of the following format:
{
timestamp: Date,
value: Number
}
The output of summation is an array of objects of the following format:
{
period: Date, // The start of the period being summed
sum: Number // The sum of values in the period
}
The output of averaging is an array of objects of the following format:
{
period: Date, // The start of the period being averaged
average: Number // The average of values in the period
}
This algorithm is weighted toward calculations that favor the end of the series array (most recent values), as it iterates from end to start.
Usage
var Aggregate = require('../index');
var endDate = new Date("June 9, 2016 GMT-0000"),
numPeriods = 2,
periodDurationInMs = Aggregate.DAY_IN_MS * 2,
series = [
{
timestamp: new Date("June 1, 2016 GMT-0000"),
value: 1
},
{
timestamp: new Date("June 2, 2016 GMT-0000"),
value: 2
},
{
timestamp: new Date("June 3, 2016 GMT-0000"),
value: 3
},
{
timestamp: new Date("June 4, 2016 GMT-0000"),
value: 4
},
{
timestamp: new Date("June 5, 2016 GMT-0000"),
value: 5
},
{
timestamp: new Date("June 6, 2016 GMT-0000"),
value: 6
},
{
timestamp: new Date("June 7, 2016 GMT-0000"),
value: 7
},
{
timestamp: new Date("June 8, 2016 GMT-0000"),
value: 8
},
{
timestamp: new Date("June 9, 2016 GMT-0000"),
value: 9
},
{
timestamp: new Date("June 10, 2016 GMT-0000"),
value: 10
},
{
timestamp: new Date("June 11, 2016 GMT-0000"),
value: 11
},
{
timestamp: new Date("June 12, 2016 GMT-0000"),
value: 12
},
];
// Aggregate the two 48-hour periods preceeding June 9th
Aggregate.sum(endDate, numPeriods, periodDurationInMs, series);