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Cycle Detected in calculation

I know JMP is not a spreadsheet and I might need to calculate this differently than I would in excel, but I cannot figure out the workaround.

 

I have a calculation where a variable is relying on itself and that gives me a "cycle detected for data column" error

I have a tank that has solution being added in over time. I know how much I have added and the tank's total volume. I also take volume out of the tank at sample times. I need to calculate how much of solution A is being removed with each sample volume. But I can't figure out how to do that without getting this cycle error. Please help!

 New Column( "Soln A Removed in Current Draw (mL)",
  Numeric,
  "Continuous",
  Formula(
   :Name( "Soln A concentration before draw (mL/L)" ) * (
   :Name( "Manually Recorded Sample Volume (mL)" ) / 1000)
  ),
 );
 New Column( "Soln A concentration before draw (mL/L)",
  Numeric,
  "Continuous",
  Formula(
   If(
    (:Name( "Soln A added (mL)" ) 
    /
    :Name( "Culture Volume Pre-Drawdown (mL)" )
    ) 
    * 1000,
    (
     (
      :Name( "Soln A added (mL)" )
      -
      Lag(
       :Name( "Cumulative Soln A Removed (mL)" ), 1 
      ) 
     )     
    /
    :Name( "Culture Volume Pre-Drawdown (mL)" )
     
    ) * 1000
   )
  ),
 );
 New Column( "Cumulative Soln A Removed (mL)",
  Numeric,
  "Continuous",
  Formula(
   Col Cumulative Sum(
    :Name( "Soln A Removed in Current Draw (mL)" ),
    :Batch Number
   )
  ),
 );
 New Column( "Soln A added per current Tank Volume (mL/L)",
  Numeric,
  "Continuous",
  Formula(
   (:Name( "Soln A added (mL)" ) * 1000) /
   :Name( "Culture Volume Pre-Drawdown (mL)" )
  ),
 );

Advanced Statistical ModelingRe: Cycle Detected in calculation

The issue appears to be that the column value for "Soln A concentration before draw (mL/L)" was always getting set to a missing value.  In JMP adding together two values where one of them is a missing value always results in a missing value.....which can be over ridden by using the Sum() function.  Here are the results I get after the change.  The changed JSL is below

Names Default To Here( 1 );
dt = Current Data Table();
dt << New Column( "Soln A Removed in Current Draw (mL)" );
dt << New Column( "Soln A concentration before draw (mL/L)" );
dt << New Column( "Cumulative Soln A Removed (mL)" );
dt << New Column( "Soln A added per current Tank Volume (mL/L)" );


For Each Row( 

// Soln A added per current Tank Volume (mL/L)
 :Name( "Soln A added per current Tank Volume (mL/L)" ) = (:Name( "Soln A added (mL)" ) * 1000) /
 :Name( "Culture Volume Pre-Drawdown (mL)" );
 
// Soln A concentration before draw (mL/L) 
 If( :Name( "Soln A added (mL)" ) / :Name( "Culture Volume Pre-Drawdown (mL)" ) * 1000,
  :Name( "Soln A concentration before draw (mL/L)" ) = Sum(
   :Name( "Soln A added (mL)" ),
   -1 * Lag( :Name( "Cumulative Soln A Removed (mL)" ) )
  ) / :Name( "Culture Volume Pre-Drawdown (mL)" ) * 1000
 );

// Soln A Removed in Current Draw (mL)
 :Name( "Soln A Removed in Current Draw (mL)" ) = :Name( "Soln A concentration before draw (mL/L)" ) * (
 :Name( "Manually Recorded Sample Volume (mL)" ) / 1000);

// Cumulative Soln A Removed (mL)
 curBatch = :Batch Number;
 curRow = Row();
 :Name( "Cumulative Soln A Removed (mL)" ) = Sum(
  :Name( "Soln A Removed in Current Draw (mL)" )[dt << get rows where( :Batch Number == curBatch & Row() <= curRow )]
 );
);

Re: Cycle Detected in calculation

I tried your method on a slightly different table (i only added the bach number column, but I think the issue is still there. Instead of an error message I get blank cells. Is there any workaround to allow a variable to rely on its last value?

Names Default To Here( 1 );
dt = Current Data Table();
dt << New Column( "Soln A Removed in Current Draw (mL)" );
dt << New Column( "Soln A concentration before draw (mL/L)" );
dt << New Column( "Cumulative Soln A Removed (mL)" );
dt << New Column( "Soln A added per current Tank Volume (mL/L)" );


For Each Row( 

// Soln A added per current Tank Volume (mL/L)
 :Name( "Soln A added per current Tank Volume (mL/L)" )  = (:Name( "Soln A added (mL)" )  * 1000) /
 :Name( "Culture Volume Pre-Drawdown (mL)" ) ;
 
// Soln A concentration before draw (mL/L) 
 If( :Name( "Soln A added (mL)" )  / :Name( "Culture Volume Pre-Drawdown (mL)" )  * 1000,
  :Name( "Soln A concentration before draw (mL/L)" )  = :Name( "Soln A added (mL)" ) 
  -Lag( :Name( "Cumulative Soln A Removed (mL)" )  ) / :Name( "Culture Volume Pre-Drawdown (mL)" )  *
  1000
 );

// Soln A Removed in Current Draw (mL)
 :Name( "Soln A Removed in Current Draw (mL)" )  = :Name( "Soln A concentration before draw (mL/L)" )  *
 (:Name( "Manually Recorded Sample Volume (mL)" )  / 1000);

// Cumulative Soln A Removed (mL)
 curBatch = :Batch Number ;
 curRow = Row();
 :Name( "Cumulative Soln A Removed (mL)" )  = Sum(
  :Name( "Soln A Removed in Current Draw (mL)" )[dt << get rows where(
   :Batch Number == curBatch & Row() <= curRow
  )]
 );
);

Re: Cycle Detected in calculation

Here is a different take on the problem.  I couldn't completely test it, given the data you provided, but I think you will see the approach I am taking, and you should be able to build upon it.

Names Default To Here( 1 );
dt = Current Data Table();
dt << New Column( "Soln A Removed in Current Draw (mL)" );
dt << New Column( "Soln A concentration before draw (mL/L)" );
dt << New Column( "Cumulative Soln A Removed (mL)" );
dt << New Column( "Soln A added per current Tank Volume (mL/L)" );


For Each Row( 

// Soln A added per current Tank Volume (mL/L)
 :Name( "Soln A added per current Tank Volume (mL/L)" )  = (:Name( "Soln A added (mL)" )  * 1000) /
 :Name( "Culture Volume Pre-Drawdown (mL)" ) ;
 
// Soln A concentration before draw (mL/L) 
 If( :Name( "Soln A added (mL)" )  / :Name( "Culture Volume Pre-Drawdown (mL)" )  * 1000,
  :Name( "Soln A concentration before draw (mL/L)" )  = :Name( "Soln A added (mL)" ) 
  -Lag( :Name( "Cumulative Soln A Removed (mL)" )  ) / :Name( "Culture Volume Pre-Drawdown (mL)" )  *
  1000
 );

// Soln A Removed in Current Draw (mL)
 :Name( "Soln A Removed in Current Draw (mL)" )  = :Name( "Soln A concentration before draw (mL/L)" )  *
 (:Name( "Manually Recorded Sample Volume (mL)" )  / 1000);

// Cumulative Soln A Removed (mL)
 curBatch = :Batch Number ;
 curRow = Row();
 :Name( "Cumulative Soln A Removed (mL)" )  = Sum(
  :Name( "Soln A Removed in Current Draw (mL)" )[dt << get rows where(
   :Batch Number == curBatch & Row() <= curRow
  )]
 );
);

 

Re: Cycle Detected in calculation

Yea it would be great if I could enter the amount removed, but I would only know the amount removed based on the current concentration which, you can see, also relies on the amount removed previously. 

Re: Cycle Detected in calculation

You are correct. JMP is not a spreadsheet.

 

You might think of a JMP data table as a collection of observations (i.e., data set). As such, each change in volume is a new row. So you might have one column to represent the volume added or removed and another to represent the current volume.

 

I think the first column, Solution A Removed in Current Draw, should be a value that is entered, not computed. That might break the cyclical references. Possibly the same for the last column, Solution A Added in Current Draw. Adjust the formulas accordingly.