How do I get my DAX measure to calculate grouped values

Question

I need help with a DAX measure in my Power BI report. I am just learning about measures, so sorry if this seems like a newbie question.

I have a simple DAX measure that I use to calculate water usage for each location/sensor, for the current date range selected in the report (via Timeline control):

Usage:= (MAX([Reading]) - MIN([Reading]))

How can I get the measure to calculate the usage, grouped by the Sensor ID?

Answer 1

Try this:

Total Usage:= SUMX( VALUES(MyTable[SensorID]), [Usage])

An alternative solution:

Total Usage:= SUMX( SUMMARIZE(MyTable, MyTable[SensorID]), [Usage])

It works the same way, only the list of unique sensor ids is returned by the SUMMARIZE function instead of VALUES.