3 Replies Latest reply on Nov 15, 2011 10:28 PM by Ahmad Fattahi

    Get interpolated data from a SQL table into AF

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      I want to use interpolated data from a SQL table in AF.  I have a some time series data in a SQL table. I link this table into AF. Now I want to see interpolated data between points know in the SQL table. E.g.
      point1:   200  1-Nov--2011
      point2:   300  1-Dec--2011


      To get interpolated data from a formulate retrieving data from 4 attributes:,
      a) value previous of the query (StartDate)
      b) value next of the query (StartDate)
      c) time of previous value (StartDate)
      d) time of next value query date (StartDate)


      So far so good, but to calculate the interpolated value at the query date I need to retrieve the Query date into a formula. That is were I got stopped. Does anyone know how to get the %StartDate% as a value in Formula data reference? Or does any know how to get interpolated data from a SQL table by configuration only, e.g. not making our own data reference?


      Thanks for your help.





        • Re: Get interpolated data from a SQL table into AF
          Ahmad Fattahi

          Please see the "Configuring the table look-up data reference" in the PI AF User manual. This is an excerpt under Interpolation in that section:


          "Use the Interpolate operator in the WHERE clause to interpolate a value for the result column based on a interpolation of the specified input column. For example, if a tank strapping table contained two columns, “Level” and “Volume”, then the configuration string “SELECT Volume FROM MyTable WHERE INTERPOLATE(Level, @MyLevelReading)” interpolates the volume based on the level reading."


          So it would basically return an interpolated value for a column based on what it reads on an input column.