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ddamico
Yak Posting Veteran
76 Posts |
 Posted - 2010-11-21 : 08:11:22
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| Good day, I have a question regarding use of statistical function specifically STDEV vs STDEVPThe code I have been tasked with porting was the followingSQRT((SQUARE(M1-M_AVG) + SQUARE(M2-M_AVG) + SQUARE(M3-M_AVG)) / 2)I wrote the aggregate using STDEV(Mn-M_AVG) since I have moved my individual M1,M2,...,Mn to separate rows.What I am really wondering is STDEV correct or should I be using STDEVP. Also, do I even need to calculate the Mn-M_AVG or is it assumed?Any help would be appreciated. |
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elwoos
Master Smack Fu Yak Hacker
2052 Posts |
Posted - 2010-11-22 : 06:21:02
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quote:
Originally posted by ddamicoWhat I am really wondering is STDEV correct or should I be using STDEVP.
It's a very very long time since I have done any statistics but if I remember rightly this depends on what you data represents. STDEV is used if it is a sample and STDEVP if it is the population. There is some more information here http://social.msdn.microsoft.com/Forums/en/sqlanalysisservices/thread/0d8edea2-f08e-41b7-b120-8ac08855c23b-----------I used to think I wasn't a morning person but it never got better in the afternoon |
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SwePeso
Patron Saint of Lost Yaks
30421 Posts |
Posted - 2010-11-22 : 06:44:27
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SQRT(POWER(M1 - M_AVG, 2.E) + POWER(M2 - M_AVG, 2.E) + POWER(M3 - M_AVG, 2.E)) / 2.E)
N 56°04'39.26"E 12°55'05.63" |
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Statistical function usage