10 Replies Latest reply: Apr 9, 2014 8:22 PM by Marco Wedel RSS

    Dual dimensions: Performance curve with data?

    Kristan Sears

      Hi all, I am VERY new to Qlikview, and really struggling to understand how to use the expressions and really pull out the power for charting.  My applications are very different from most of the sales data that is out there.  I typically only have/need one dimension, i.e. Date, Power, Flow.  My goal is to graph a performance curve (for which I have data of Power vs. Speed, or some similar correlation).  I also have real operating data that I would like to plot on the same chart, so that I can see how the unit is performing with respect to its design.  I have been able to create the performance curve, but I'm not able to successfully plot the data on the same curve.  The data uses a different Power dimension than the Performance curve.

       

      Any help would be greatly appreciated

       

      Turbine data Performance curve.png

        • Re: Dual dimensions: Performance curve with data?
          Toni Kautto

          Would it be possible for you to provide a sample QVW file with some example data? This would make it easier to suggest a solution or way forward.

           

          If possible please clarify what the expected chart result should look like, as I am not sure I completely got the intention or problem in your screenshot.

          • Re: Dual dimensions: Performance curve with data?
            Marco Wedel

            Hi Kristan,

             

            nice to meet a fellow engineer over here.

             

            Here is one possible solution:

             

            Binary [http://community.qlik.com/servlet/JiveServlet/download/504736-100957/Performance%20Curve%20Sample.qvw];
            
            SET ThousandSep='.';
            SET DecimalSep=',';
            SET MoneyThousandSep='.';
            SET MoneyDecimalSep=',';
            SET MoneyFormat='#.##0,00 €;-#.##0,00 €';
            SET TimeFormat='hh:mm:ss';
            SET DateFormat='DD.MM.YYYY';
            SET TimestampFormat='DD.MM.YYYY hh:mm:ss[.fff]';
            SET MonthNames='Jan;Feb;Mrz;Apr;Mai;Jun;Jul;Aug;Sep;Okt;Nov;Dez';
            SET DayNames='Mo;Di;Mi;Do;Fr;Sa;So';
            
            RENAME Table Sheet1 to tabUMassSTG1Efficiency;
            RENAME Table [Sheet1-1] to tabPerformanceData;
            
            tabData:
            LOAD
              [Turbine Power (kW)] as [Power (kW)],
              Avg([STG1_Inlet_Steam_Flow]) as [Flow (lbm/hr)],
              'measured' as DataType
            Resident tabPerformanceData
            Group By [Turbine Power (kW)];
            
            LOAD
              Power as [Power (kW)],
              [Flow rate] as [Flow (lbm/hr)],
              'calculated' as DataType
            Resident tabUMassSTG1Efficiency;
            
            
            

             

             

            QlikCommunity_Thread_113573_Pic1.JPG.jpg

             

            To create a scatter plot, you need to use e.g. the date field as the dimension and the flow and power as expressions.

            That's why you get this missing expression message.

            I included an example for this chart also:

             

            QlikCommunity_Thread_113573_Pic2.JPG.jpg

             

            hope this might help

             

            regards

             

            Marco

              • Re: Re: Dual dimensions: Performance curve with data?
                Kristan Sears

                Marco, thanks so much.  This helps a lot.  I was hoping I would bump into a fellow engineer who could point me in the right direction.

                 

                I am still trying to learn the scripting language, so I hope you'll bear with me as I ask a couple of questions

                1. Why the binary header?  what function does that serve?  I have seen references to "binary" in others posts.
                2. Why rename the sheets?  Is it confusing Qlikview to have data from two sources called "Sheet1"?
                3. Why do you take the Avg([STG1_Inlet_Steam_Flow])?
                4. Can you explain the Resident and Group By functions?  I looked them up, but I don't fully understand how those are being used here.

                 

                 

                Thanks again,

                -Kristan

                  • Re: Dual dimensions: Performance curve with data?
                    Marco Wedel

                    Hi Kristan,

                     

                    1. I used the binary load for convenience purposes only. It was the easiest way to load the data into my application, because I didn't have your Excel sources. You wouldn't use this load in your application though.

                     

                    2. renaming the sheets was just done for a better readability of the code. QlikView doesn't matter, what names the tables have.

                     

                    3. I created an additional table that did not include the date field, so I had to combine the power and flow fields. There are a few cases with more than one flow value per power value, so I used the average flow.

                     

                    4. the resident load simply loads data from already loaded tables. Using the binary load I had all the data in the application. To create a combined table for measured and calculated values, I used the resident load.

                    The "group by" bit is needed because of the aggregation (avg flow) in this load statement.

                    This load says "create a table, that contains all distinct power values and the average flow values for each of them"

                     

                    hope this clarifies a bit.

                     

                    regards

                     

                    Marco

                  • Re: Re: Dual dimensions: Performance curve with data?
                    Kristan Sears

                    Marco,

                         Another question.  I have 1-year of data, loaded from a CSV file for each day, now stored in a .QVD file.  The file is too large for me to post.  For the portion of the script that handles the actual turbine data,

                     

                    1. tabData: 
                    2. LOAD 
                    3.   [Turbine Power (kW)] as [Power (kW)], 
                    4.   Avg([STG1_Inlet_Steam_Flow]) as [Flow (lbm/hr)], 
                    5.   'measured' as DataType 
                    6. Resident tabPerformanceData 
                    7. Group By [Turbine Power (kW)]; 

                     

                    If this is coming from the QVD, how would I modify this to handle that?

                    Thanks again for all your help.

                    -Kristan

                  • Re: Dual dimensions: Performance curve with data?

                    To get rid of the steep graph and get a curved shape. Try selecting Polynomial of 3rd degree.