Hello.
These calculated measures are a bit problematic. We already had multiple conversations about this issue.
The thing is that these measures can have not only SUM, COUNT, AVG functions, but also complicated functions like: = (A/B * 100) - 50.
We would like such scenarios to also be handled.
A bit of how ZoomCharts drilldown works....
So each time new categories or chart options are changed, ZoomCharts receives new data from Power BI. If other charts work as filters and the data is filtered then ZoomCharts receives only that filtered data. And all that data is displayed on the chart.
Let's say that lowest grain of data is minutes. But we have a lot of data and we can display it also in hours, days, months, years. When ZoomCharts receives the data in minutes, then in that grain all calculated fields are correct as such formulas are executed before giving them to ZoomCharts.
Now all data is loaded into chart. ZoomCharts unfortunately doesn't know the formula for those calculated measures. And ZoomCharts for performance reasons works with all that data that it has without requesting new data each time drill down level is changed. (In SDK it is possible, but currently it seems that in Power BI it would always return the same data).
So ZoomCharts aggregates the data itself and by default aggregation method is SUM. For example, when you change drill down grain from minutes to hours, then by default for all data is summed up.
Here are all methods that we support:
"sum" | "min" | "max" | "first" | "last" | "avg" | "count"
Such custom formulas like: =(A/B * 100) - 50 currently seems to be complicated to support as there can be anything. And it seems that Power BI doesn't provide the formula so user would have to write it somewhere in chart configuration. Theoretically that could be possible.
The idea that we could add additional aggregation method options for each series could solve the issue if you are interested in these aggregation methods:
"sum" | "min" | "max" | "first" | "last" | "avg" | "count"
We will have to make some tests and see if that could work also with calculated measures.
Eizens