Function library

Joule math functions

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Averages

Exponential Moving Average

An exponential moving average (EMA), also known as an exponentially weighted moving average (EWMA),[5] is a first-order infinite impulse response filter that applies weighting factors which decrease exponentially. The weighting for each older datum decreases exponentially, never reaching zero. This formulation is according to Hunter (1986) [wikipedia].

Attribute	Description	Data Type	Required
fields	Fields to calculated from the event	String[]
event history	Number of rolling events to stored and used for the calculation	Integer
assign prefix		String Default: Function postfix

Weighted Moving Average

A weighted average is an average that has multiplying factors to give different weights to data at different positions in the sample window. Mathematically, the weighted moving average is the convolution of the data with a fixed weighting function [wikipedia].

Simple Moving Average

In financial applications a simple moving average (SMA) is the unweighted mean of the previous 𝑘 data-points. However, in science and engineering, the mean is normally taken from an equal number of data on either side of a central value. This ensures that variations in the mean are aligned with the variations in the data rather than being shifted in time [wikipedia].