Product Features
...
Analytics
Statistical Functions

Feature Extractor

3min

The Feature Extractor processor extracts meaningful patterns and characteristics from raw PLC data, transforming complex data into features that advanced analytic models can easily understand and utilize.

Feature Extractor Overview

  • Let's say you picked a window of N values:
  • Minimum: Gives you minimum of N values
  • Maximum: Gives you maximum of N values
  • Average: Gives you the average(mean) of N values
  • Standard Deviation : squareRoot( (x - average)^2/(N-1) )
  • Variance : (x - average)^2/(N-1)
  • Median : N/2 for odd number of window elements, {[N-1] + [N]}/2 for even window elements
  • Kurtosis : [ (N)(N+1) / (N-1)(N-2)(N-3) ] * SIGMA [(x_i - x_avg)/(stdDeviation) ^4]
  • Skewness : [ (N) / (N-1)(N-2)] * SIGMA [(x_i - x_avg)/(stdDeviation) ^3]
  • Zero crossing rate: Gives you how many times the signal has crossed zero i.e positive value to negative, OR negative value to positive
  • Root Mean Square : squareRoot[ SIGMA x^2 / N]
  • Quartiles: Divides the signal into 4 equal quartiles, based on medians
  • Inter-quartile Range: Difference between the third quartile and first quartile
  • Mean Absolute Deviation : abs(x - average)/(N)
  • Average absolute variation : abs(x - average)/(N)
  • The timer interval parameter is useful if the connected input tag is currently not polling, but you still want this KPI to publish a value every few seconds, defined by the aforementioned timer.
  • If you know your input is going to publish at the expected interval, it is better to disable this timer by entering 0 in the field.

Feature Extractor Parameters

Parameters

Details

Window Size

This parameter specifies the window in which to calculate the features, represented in seconds.

Minimum Maximum Average Standard Deviation Variance Median Kurtosis Skewness Zero Crossing Rate Root Mean Square Quartiles Inter Quartile Range Mean Absolute Deviation Average Absolute Variation

Minimum: It gives the minimum value within the specified window size. Maximum: This parameter gives you the maximum value within the specified window size. Average: It calculates the average (mean) of the values within the window size. Standard Deviation: This parameter computes the standard deviation of the values within the window. Variance: It calculates the variance of the values within the window. Median: This parameter gives you the median of the values within the window. Kurtosis: Kurtosis measures the "heaviness" of the tails of the distribution of values within the window. Skewness: Skewness measures the asymmetry of the distribution of values within the window. Zero Crossing Rate: It determines the number of times the signal crosses zero within the window. Root Mean Square: This parameter calculates the root mean square of the values within the window. Quartiles: It divides the signal into four equal quartiles based on the medians within the window. Inter-Quartile Range: This parameter determines the difference between the third quartile and the first quartile within the window. Mean Absolute Deviation: It calculates the mean absolute deviation of the values within the window. Average Absolute Variation: This parameter calculates the average absolute variation of the values within the window.

Timer Interval

This parameter allows you to set the timer in milliseconds. It's useful for continuous output display when no event is triggering the expression.

Pass Through Value

The Pass Through Value parameter enables you to specify how anomalous data should be handled.

Feature Extractor Parameters
Feature Extractor Parameters


Note: When creating an analytics flow with Feature Extractor processor, refer the Use the Feature Extractor Function guide for more details.