I am doing a relatively simple bar diagram to show the expected change in use of a substance in the next 6 months. Each record (doctor) has a number which can be positive to show an increase or negative to show a decrease in use. I have taken the mean value without any weight to show the overall expected change.
However, here is the problem - the positive values are being calculated and the average taken and it appears as if the negative values are being calculated separately. This means I have one doctor with a -50% and his value is shown as -50% whilst the other 13 doctors have positive values where the mean of all their values is taken at 27%.
I now have a total value of -22.9%, which is not correct. I have tried aggregating but can't seem to get rid of the -50%.
Not sure what method you used to calculate the mean? Formula in the DataManager, Table in Data Explorer, or Formula as a measure in the Bar/Line view? It is better to use a formula field, in which case I cannot reproduce the issue.
Sum of means is difficult to interpret, so depending on the scenario perhaps you could try different method, either comparing the outcome of the individual categories (+/-%) or calculating a single weighted mean figure as a global indicator.