4 Replies Latest reply on Sep 22, 2013 1:13 PM by c n

    calculating by date

    c n

      I am trying to create a dashboard for telephony grade of service GOS, displayed over time. Simplified i have 3 columns of data, (1) daily date, (2) calls handled, & (3) calls outside grade. The calculation for GOS is ((2)-(3))/(2). How do I achieve an accurate calculation of GOS graphed in a chart, that adjusts as the date is either filtered, or changed from daily, to monthly, the quarterly etc?

        • 1. Re: calculating by date
          Matt Lutton

          Simply write the calculation you've described, use it in a viz, and use the daily date field in your viz and as a filter.  You can use the daily date to filter at the daily level, monthly, quarterly, etc based on a calendar year.  You can also change the date to display at different aggregations in your visualization. If you need to adjust the calendar, there are some ways to do that as well.


          Attached is a very simple example of three sheets, all driven by the same date at different levels.  This took no time at all.  You could create just one sheet, and use a parameter to allow users to choose the daily, monthly, quarterly, etc. levels as well.  I've set up simple examples in the attached--this is using the Coffee Chain data source, so daily and monthly look the same since the dates include one day from each month.


          I hope this is helpful in some way.  There's a lot of functionality available when using dates.  Best of luck.

          • 2. Re: calculating by date
            c n

            Hi Matthew


            Thanks for your reply. Unfortuntaley the formula i used seems to be summing differently than expected. When I use the data in excel to calculate I am able to achieve correct results. I need the applicable calls handled and calls outside grade summed for the selected period, before the calculation is applied.


            Also, you use terminology "viz". What is this?

            • 3. Re: calculating by date
              Matt Lutton

              I just attached a workbook to my original post.  A viz is just a "visualization", or worksheet in Tableau.


              Can you attach your workbook?  If not, copy and paste your calculated field code here.  You may need to use sum([FieldName) for your calcs, if you aren't already.

              • 4. Re: calculating by date
                c n

                thanks for your help Matthew. Success!