Detailed Description

MovingAverage operator that averages input values over given Time to produce output.

This operator can be used to calculate average (mean) of a value. Operator observes input values values in configurable amount of Time and calculates average value output based on input values in that "observation window".

Arguments

Properties

When operator is used inside a signal its default input is automatically tied to signal's InternalValue or previous operator's output. Its default output is automatically tied to next operator's input or to signal's Value. See also CDP Operator Usage In CDP Signals.

Examples

Simple Moving Average Example

Below is an example plot with the MovingAverage(HistoryWindowTime=10, AverageType="Simple") (orange) of the Sine(Frequency=0.1 Hz) signal (cyan) in input. Note, that as the HistoryTimeWindow is exactly the same as sine cycle (10 s) then value will be averaged to 0 after one sine cycle.

Median Moving Average Example

Below is an example plot with the MovingAverage(HistoryWindowTime=0.5, AverageType="Median") (orange) of the noisy Sine(Frequency=0.1 Hz) signal (cyan) in input. Note, that the Median average can successfully be used to filter out random noise.

Weighted Moving Average Example

Below is an example plot with the MovingAverage(HistoryWindowTime=10, AverageType="Weighted") (orange) of the Sine(Frequency=0.1 Hz) signal (cyan) in input. Note, that in that case output will never be averaged to 0 because of the HistoryWindowTime youngest values contribute more than the oldest values.

Cumulative Average Example

Below is an example plot with the MovingAverage(HistoryWindowTime=10, AverageType="Cumulative") (orange) of the Sine(Frequency=0.1 Hz) signal (cyan) in input. Note, that in that case the average will approach 0 very slowly and continuously because all sine values are taken into account (not only those that were evaluated during HistoryWindowTime).

RMS Average Example

Below is an example plot with the MovingAverage(HistoryWindowTime=10, AverageType="RMS") applied, shown as orange, while the input signal, Sine(Frequency=0.1 Hz, Amplitude=1), is shown as cyan. Note, that since the HistoryTimeWindow is exactly the same as the sine cycle (10 s), then the value will be approximately 0.707, which is the constant for RMS / amplitude for any sine wave.

Actual Processing Code of the MovingAverage

unsigned int MovingAverage<T>::Process()
{
  auto windowSize = d->valueHistory->GetWindowTime();
  if (windowSize < 0.0)
  {
    GetParent()->ReportConfigurationFault(this, "Negative window Time");
    d->faultReported = true;
    return STATUS_SIGNAL_FAULT;
  }
  if (d->valueHistory->GetReset())
    d->ResetCalculation();

  d->valueHistory->PushValue((T)m_input);

  m_output = d->CalculateAverage((T)m_input);

  if (d->faultReported)
  {
    GetParent()->ClearConfigurationFault(this);
    d->faultReported = false;
  }

  return STATUS_OK;
}