time-series-collection
v1.2.0
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A tiny, blazing-fast time series collection library with zero dependencies (did I get that right?)
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Time Series Collection
A tiny, blazing fast, time series collection with zero dependencies! (did I get that right?)
This library uses unix timestamps (the number of seconds since the epoch)
Getting Started
import { TimeSeriesCollection } from 'time-series-collection';
// instantiate a new collection
const collection = new TimeSeriesCollection<number>();
// you put some samples in
collection.addSample(unixTime, 50);
collection.addSample(anotherUnixTime, 100);
collection.addSample(aDifferentUnixTime, 150);
// and you get some samples out
collection.getValue(anotherUnixTime); // 100
Interpolation Algorithms
An interpolator function is used to produce a value when there's no exact match. A few interpolator functions are provided, but you can write your own too!
import { TimeSeriesCollection, closestSample } from 'time-series-collection';
// create a simple interpolator
const interpolatorFn = closestSample();
// instantiate a collection with the interpolator
const collection = new TimeSeriesCollection<number>(interpolatorFn);
// add some samples
collection.addSample(100, 17);
collection.addSample(200, 23);
// always retrieve the closest sample
collection.getValue(0); // 17
collection.getValue(105); // 17
collection.getValue(2403); // 23
Functional API
All the methods of the class are also exposed as functions (although currently these functions do mutate the collection for memory efficiency and performance)
import { TimeSeriesCollectionInterface, addSample, removeTimeFrame } from 'time-series-collection';
// create a collection data structure
const collection: TimeSeriesCollectionInterface<number> = {
timestamps: [],
datums: []
};
// add some samples
addSample(collection, unixTime, 42);
addSample(collection, anotherUnixTime, 38);
// retrieve a value
getValue(collection, unixTime); // 42
Documentation
Class TimeSeriesCollection
constructor<T>(interpolator)
Creates a new instance of a TimeSeriesCollection
| Parameter | Type | Description | |
| ---- | ---- | ----------- | -------- |
| interpolator | Interpolator
| The interpolator to use when getting a value
addSample(timestamp, data)
Adds a sample to the collection
| Parameter | Type | Description | |
| ---- | ---- | ----------- | -------- |
| timestamp | number
| The unix timestamp for this sample
| data | T
| The data for this sample | |
addSamples(timestamps, datums)
Adds a list of samples to the collection. The samples do not have to be sorted, but if they are sorted, they will be inserted much faster.
| Parameter | Type | Description | |
| ---- | ---- | ----------- | -------- |
| timestamps | Array<number>
| The list of timestamps to insert
| datums | Array<T>
| The matching order list of datums to insert | |
removeTimeFrame(fromTimestampInclusive, toTimestampInclusive, keepClosestSamples)
Removes all samples inside the specified time frame
| Parameter | Type | Description | |
| ---- | ---- | ----------- | -------- |
| fromTimestampInclusive | number
| removes all samples after or at this unix time| |
| toTimestampInclusive | number
| removes all samples before or at this unix time | |
| keepClosestSamples | boolean
| whether to keep a single sample of either side of the time frames to remove. | |
removeOutsideTimeFrame(fromTimestampInclusive, toTimestampInclusive, keepClosestSamples)
Removes all samples outside of the specified time frame
| Parameter | Type | Description | |
| ---- | ---- | ----------- | -------- |
| fromTimestampInclusive | number
| removes all samples before or at this unix time | |
| toTimestampInclusive | number
| removes all samples after or at this unix time | |
| keepClosestSamples | boolean
| whether to keep a single sample of either side of the time frames to remove. | |
Interpolators
closestSample(maxForwardDistance, maxBackwardsDistance, favourPastSamples)
An interpolator factory function which picks the closest sample, given some constraints
| Parameter | Type | Description | |
| ---- | ---- | ----------- | -------- |
| maxForwardDistance | number
| Ignore samples more than this many seconds before the target timestamp (inclusive) | |
| maxBackwardsDistance | number
| Ignore samples more than this many seconds after the target timestamp (inclusive) | |
| favourPastSamples | boolean
| Whether to favour past samples of future samples in the case of an exact match | |
closestFutureSample(maxDistance)
An interpolator factory function which picks the closest sample in the future
| Parameter | Type | Description | |
| ---- | ---- | ----------- | -------- |
| maxDistance | number
| Ignore samples more than this many seconds after the target timestamp (inclusive) | |
closestPastSample(maxDistance)
An interpolator factory function which picks the closest sample from the past
| Parameter | Type | Description | |
| ---- | ---- | ----------- | -------- |
| maxDistance | number
| Ignore samples more than this many seconds before the target timestamp (inclusive) | |