2 Replies Latest reply on Aug 1, 2018 9:23 PM by MitchGarside

    AF analysis using standard deviation and filtered values

    MitchGarside

      I currently create daily filtered averages for many process parameters by having an AF attribute which creates a filtered version of the parameter (using an AF formula, and everything outside of limits =0), followed by a daily analysis which creates a daily average of this filtered value when it is >0. I would also like to create a daily standard deviation using the same filtered value, however, because the attribute used in the standard deviation formula has to be an AF attribute, I cannot figure out a way to remove these zero value from the analysis. on days where the parameters are outside of these limits, I end up with a large standard deviation as the filtered values contains several 0 values.

       

      Is there anyway to filter properly for data going into a standard deviation analysis?