Help with an STDEV expression

[PhilKing01]

Hi, 

Hoping this is a simple answer. In summary, the STDEV expression I have below is not working. 

=vAvgLine_SSNAPCBOnSceneDuration

+ StDev (aggr (

avg 

( { < [Duration Clock Start to OnScene] = { '>0' } ,

[Duration Clock Start to OnScene] =   { "=min ( [Duration Clock Start to OnScene] ) "  },

[Responder Primary Sub-Type]  = {'AMB', 'RRV' , 'DECA' } ,

[Duration On Scene] = { '>0' } ,

[Duration On Scene] =   { "=min ( [Duration On Scene]  ) "  }

> }  

( [Duration On Scene]    /  86400 ) 

) ,  [Year And Month Sort]

) 

)

*

vStdDev

- Where 'vAvgLine_SSNAPCBOnSceneDuration' is :

avg 

( aggr (

min ( { < [Duration Clock Start to OnScene] = { '>0' } ,

[Duration Clock Start to OnScene] =   { "=min ( [Duration Clock Start to OnScene] ) "  },

[Responder Primary Sub-Type]  = {'AMB', 'RRV' , 'DECA' } ,

[Duration On Scene] = { '>0' } ,

[Duration On Scene] =   { "=min ( [Duration On Scene]  ) "  }

> }  

( [Duration On Scene]    /  86400 ) 

), [Source Call Number], [Year And Month Sort]

) 

)

I've done this for other similar measures (which were more simple e.g. the avg ( aggr (avg (fieldname) , yearmonth) ) but the above has me stumped. What would be the solution?

(I can't share the data due to confidential reasons). 

Thanks in advance. 

[Anil_Babu_Samineni]

Try to debug the expression step by step and see if you able to get the result individually and see where is the fault? 

[PhilKing01]

Hi Anil, 

I've previously tried too. 

The expression above '+ stdev' returns results on its own. When I add ' + stdev (1) ' to it, it also returns results. 

I suspect that the error is being caused by the (aggr ( avg ( .... part. I can't figure out where I need a 'sum' or 'min' or similar to make this second part work. 

... + StDev (aggr

   (

      avg 

      ( { <  ....  > }  ( [Duration On Scene]    /  86400 ) 

   ) ,  [Year And Month Sort]

 ) 

)

*

vStdDev

[Anil_Babu_Samineni]

Without understanding the business logics, I have limited offer for you . But I will give the idea, Let's assume you are aggregating the data against medium. You can perhaps do Avg(Aggr(Median(....), Field))

[PhilKing01 · Accepted solution]

Thanks Anil, having looked through similar expressions and intentions with a colleague, it seems the Variable doesn't like to work when used within the expression. Thank you for your interest though.