node-red-nodes/function/smooth/README.md

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node-red-node-smooth

A Node-RED node that provides several simple smoothing algorithms for incoming data values. These include

  • Minimum
  • Maximum
  • Mean
  • Standard Deviation
  • High Pass Smoothing
  • Loww Pass Smoothing

Install

Run the following command in your Node-RED user directory - typically ~/.node-red

npm install node-red-node-smooth

Usage

A simple node to provide various functions across several previous values, including max, min, mean, standard deviation, high and low pass filters.

Max, Min, Mean and Standard Deviation work over a rolling window, based on a specified number of previous values.

The High and Low pass filters use a smoothing factor. The higher the number the more the smoothing. E.g. a value of 10 is similar to an α of 0.1. It is analogous to an RC time constant - but there is no time component to this as the code is based on events arriving.

Note: This node only operates on numbers. Anything else will try to be made into a number and rejected if that fails.