Gaussian Filter
The Gaussian Filter processor smooths a signal using a Gaussian (bell-curve) weighting function.
Why use Gaussian Filter
Use this processor to reduce noise in a signal while preserving its underlying trend, for example, smoothing a noisy sensor reading before it reaches a dashboard or a downstream calculation.
How it works
The processor calculates the mean and standard deviation of the current window of values, then uses them to weight the current value: values closer to the window's mean carry more weight, and values farther from it carry less.
Specifically, it calculates a coefficient as 1 / (sqrt(2π) × standard deviation) and an exponential term as exp(-1/2 × (current - mean)² / standard deviation²). Multiplying the coefficient by the exponential term gives the filtered value.
If your input tag doesn't publish at a steady rate, use Timer Interval to publish a value on a fixed schedule instead of waiting for the next incoming event. If your input already publishes at the interval you expect, enter 0 to disable the timer.
Parameters
Parameter | Details |
|---|---|
Window Size | The window (in seconds) over which the Gaussian filter calculates the mean and standard deviation. |
Timer Interval | Sets a timer (in milliseconds) that continuously publishes the output when no event triggers the filter. Enter 0 to disable the timer. |
Pass Through Value | Determines whether the processor's output is the filtered value or the original unchanged input value. |