--  Computes the variance over a table of values
--
--  VAR.P : variance over the entire population
--  VAR.S : variance over a sample of the entire population
--
--  VARX is an iterator, VAR is the simplified version in case
--  you are using a single column
DEFINE
    TABLE SampleData = { 2, 4, 4, 4, 5, 5, 7, 9 }
EVALUATE
{
     ( "VAR.P",  VAR.P ( SampleData[Value] ) ),
     ( "VAR.S",  VAR.S ( SampleData[Value] ) ),
     ( "VARX.P", VARX.P ( SampleData, SampleData[Value] ) ),
     ( "VARX.S", VARX.S ( SampleData, SampleData[Value] ) ),
     ( "VARX.P", VARX.P ( Sales, Sales[Quantity] * Sales[Net Price] ) ),
     ( "VARX.S", VARX.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 smaller because
-- the set used has 100,000 rows