Exponential Waveform Average

Controls: Wave Avg Dialog >> Exponential
Macro: WavgMode=Exp

Sometimes you may just want to monitor an experiment or process without having discrete averages that must be started and stopped. But if the signal has a lot of noise, you can't really see what's going on. Exponential averaging provides a continuous average which looks like the normal Linear averager output, only it is always "live". It is a weighted average of multiple frames, with more recent data having more influence on the result and very old data being effectively ignored. In this way, you can get a better view of the desired signal, at the cost of slow response to a sudden change.

Exponential averaging is identical to Linear averaging until the requested frames value is reached. After that the averager continues to operate in exponential mode, with the requested frames value acting like a time constant. Larger time constants cause the average to react more slowly to changes in the signal, since there are more old frames contributing to the total.

A running exponential average will show the total number of frames accumulated in the Total Frames Counter (beneath the Averager button). When the total reaches the requested time constant, the value will stop increasing and will show 'TC' after it to indicate that the time constant is in effect. It will be cleared when the average is abandoned by toggling the Averager off.

Macro Notes:

WavgMode=Exp or WavgMode=1 sets Exponential mode. See Macro Notes under Waveform Averager Mode for the complete list of mode numbers and names.

See also Averager, Waveform Averager Mode, Waveform Averager Controls, and Linear Waveform Average.