Forum Discussion

TMO_KY's avatar
TMO_KY
Helper II
2 years ago

StDev discrepancy when using similar tables

I wasn't exactly sure how to word my problem to make it stand out from similar but different issues.  Anyway, I have a DAX table that I created and it works flawlessly but I was recently asked if I c...
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lbendlin's avatar
lbendlin
Super User
2 years ago

In your TEST table each failure has its own row, therefore the standard deviation is computed across all these 1 values. You need to use STDEVX.P rather than STDEV.P 

 

Having said that I can only get half of it to work.

 

 

  • TMO_KY's avatar
    TMO_KY
    Helper II
    2 years ago

    That's more than where I was able to get so I appreciate it.  I'll have to talk to my end user and get their thoughts. if the Product Family will be in a visual or not.  I know it's used as a filter sometimes but not always.

    What if there was a sum measure for the Failures in the test table and do the stdevx against a measure?

    • lbendlin's avatar
      lbendlin
      Super User
      2 years ago

      I think that should work, as long as that measure evaluates for each row of the table argument in STDEVX.P .  The trick here is to present a suitable table - which can also be a table variable.

      • TMO_KY's avatar
        TMO_KY
        Helper II
        2 years ago

        I appreciate the insight.....and I need to see what's going on, your suggestion worked for the data I provided (hard-coded in query) but once put in with live data, it throws different values, even when filtered, and all data types are the same.  Either way, I appreciate the help and quick responses.