9 Replies Latest reply on Jun 18, 2018 7:49 AM by Jim Dehner

    How to calculate an area of a polygon

    Jose Gila

      Hello Community,

       

      I have a question. I would like to know how to calculate the blue area created in this polygon (see image). Would it be possible? My idea would be to give it a value from 0 to 100 and use it as a filter to find "who's the best player", for example. I've been struggling with this and it was impossible... I'm sure it doesn't have to be so difficult! Thank you very much in advance if someone could help me with this.

       

      THANK YOU!

       

      Captura de pantalla 2018-06-16 a las 13.17.34.png

        • 1. Re: How to calculate an area of a polygon
          Jim Dehner

          Good morning Jose

           

          I think this might work - each of the individual areas is a triangle - the area of the triangle is 1/2 x base x height

          for any the triangle that starts at 12:00 and goes to 1:00  the 2 sides are defined as a value that represents like Goals (say A in the formula below)  or % conversion (B in the formula)-

          don't know how you did that but you have those values -

          the base will me max(A,B) and teh height will be abs((A-B))/2

           

          you would find A and B values by using lookup(dimension,0) and Lookup(dimension,1)

           

          then you would sum each of the triangles - think like doing a window sum of the calculated field

           

          Let me know if that helped

          Jim

          If this posts assists in resolving the question, please mark it helpful or as the 'correct answer' if it resolves the question. This will help other users find the same answer/resolution.  Thank you.

          • 2. Re: How to calculate an area of a polygon
            Jim Dehner

            Thinking about it a little more it would make sense for A  to be the max() of the 2 sides and B to be the Mni()

             

            Jim

            • 3. Re: How to calculate an area of a polygon
              Jose Gila

              Hi Jim,

              Thank you very much for your answer. I've been trying it for some hours, but unfortunately I couldn't get it...

              Send you the file here clean in case you could have a look and try with your method creating a calculated field. My aim would be to get a value between 0-100 for each player.

              I'm gonna continue trying... thank you so much again!

              Jose

              • 4. Re: How to calculate an area of a polygon
                Jose Gila

                (I added the file at the first comment, sorry).

                Thank you again.

                • 5. Re: How to calculate an area of a polygon
                  Jim Dehner

                  see the attached

                  I am not a statistician so I don't know the process you are using and with the 3 data sources and some of the formating it gets a little confusing

                   

                  I think your "Stat Values" are actually percentages of the  and there are 12 of them

                  I converted the formulas I game you before into this

                   

                  and

                   

                  The area is divided by 100 to correct for the percentage format (or lack thereof in the vis )

                   

                   

                  now for the total I think it is a weighted average based on the percent percentages - there are 12 segments each with equal weight

                   

                   

                  I think this is correct - you can check it against something you know

                   

                  in text table form it returns this

                  for your radar chart like this

                   

                  Jim

                  If this posts assists in resolving the question, please mark it helpful or as the 'correct answer' if it resolves the question. This will help other users find the same answer/resolution.  Thank you.

                  • 6. Re: How to calculate an area of a polygon
                    Jose Gila

                    Thank you so much! You are really kind. I'm gonna trying this now, even though I can't open your attached file

                    I'll let you know. Thank you again.

                    • 7. Re: How to calculate an area of a polygon
                      Jim Dehner

                      Good morning

                      Gave this some more thought over the weekend

                      I think the Height value was incorrect - it should be this

                       

                      Making the outcome this

                       

                       

                      the file is attached again as a 10.2 twbx workbook

                      Jim

                      • 8. Re: How to calculate an area of a polygon
                        Jose Gila

                        That's awesome, Jim! Thank you very much.

                         

                        It makes now sense and it's great. I would like to use this value as a filter too, but when I create a new sheet and add it, this happen:

                         

                        Captura de pantalla 2018-06-18 a las 16.30.57.png

                         

                        It changes to a superior value of 100. It's ok, because it keeps the scale and the best ones (Reyes - Guardiola) have a higher value, but would be so good between 0-100.

                         

                        My final aim would be to use this "total area" as a "Total Index" in order to "rate" the players. Imagine this with a database of 10,000 players and use the filter to get who are "the best". That'd be amazing.

                         

                        Captura de pantalla 2018-06-18 a las 16.27.47.png

                         

                        Thank you very much!

                        • 9. Re: How to calculate an area of a polygon
                          Jim Dehner

                          Glad to help

                          your question was how to determine the area of the polygon -

                          further questions about the meaning of the data are a different issue

                           

                          If the post helped you or gave you the path on how to determine the area please mark my initial response correct to close the thread

                          Thanks

                          Jim