--  Computes the standard deviation over a table of values
--
--  STDEV.P : standard deviation over the entire population
--  STDEV.S : standard deviation over a sample of the entire population
--
--  STDEVX is an iterator, STDEV is the simplified version in case
--  you are using a single column.
DEFINE
    TABLE SampleData = { 2, 4, 4, 4, 5, 5, 7, 9 }
EVALUATE
{
     ( "STDEV.P",  STDEV.P ( SampleData[Value] ) ),
     ( "STDEV.S",  STDEV.S ( SampleData[Value] ) ),
     ( "STDEVX.P", STDEVX.P ( SampleData, SampleData[Value] ) ),
     ( "STDEVX.S", STDEVX.S ( SampleData, SampleData[Value] ) ),
     ( "STDEVX.P", STDEVX.P ( Sales, Sales[Quantity] * Sales[Net Price] ) ),
     ( "STDEVX.S", STDEVX.S ( Sales, Sales[Quantity] * Sales[Net Price] ) )
}

-- The STDEV.S over SampleData is very different from STDEV.P because the 
-- set is small (8 rows for the population, 8 rows for the sample)
-- When applied to Sales, the difference is small in hidden decimals because
-- the set used has 100,000 rows