Need an object or function to compute a Running Average

Question

Each minute, I must compute the average of the 180 most recent values for a parameter, each of which was computed at one-minute intervals from current measurements. Referred to as a 3-hour Running Average, this is commonly used with environmental measurements. Other (shorter) time periods are also used. Some of the one-minute values are themselves averages of the values sampled during the minute, some are the maximum or minimum value found during the minute.
Any suggestions of how to do it within Lookout?

Answer 1

Greetings,
From what you have described, it sounds as if you need more of a rolling average instead of a running average. Unfortunately we don't have an object to direct accomplish this for you, and it is a little more difficult when you key in the fact that you need to average 180 elements. In order to implement this though, it will take a little time and effort to utilize a combination of objects and expressions. Two methods come to mind:
1. Use a Sequencer object to multiplex through 6 different Sample objects. You know that the averages occur once a minute so you can set up your Sequencer to write a average to a Sample object, then transition to the next state and write the next average to the next Sample object and so forth. Then create an express
ion that adds up the first 30 elements of the 6 sample objects and divide by 180.
2. Daisy-chain 6 Sample objects together. You could use 5 expressions to write the 35th element of 1 Sample object to the 1st element of the next Sample object. Then create an expression that adds up the 35 elements of the first 5 Sample objects and the first 5 elements of the 6th, then divide by 180.
Hope this helps.
Patrick R.