really add tests
This commit is contained in:
parent
07280321ab
commit
d00e71309d
@ -2,16 +2,12 @@
|
||||
-- http://mathworld.wolfram.com/UniformDistribution.html
|
||||
|
||||
With dist As (
|
||||
SELECT random() As val
|
||||
SELECT random()::numeric As val
|
||||
FROM generate_series(1,5000000) t
|
||||
),
|
||||
m As (
|
||||
SELECT avg(val) mn, count(*) cnt, stddev(val) s
|
||||
FROM dist
|
||||
)
|
||||
|
||||
SELECT
|
||||
abs(sum(power(mn - val,4)) / ( cnt * power(s,4)) - 3 + 1.20) < 1e-3 As kurtosis,
|
||||
abs(sum(power(mn - val,3)) / ( cnt * power(s,3))) < 1e-3 As skewness
|
||||
FROM dist, m
|
||||
GROUP BY m.cnt, m.mn, m.s
|
||||
-- does random dist values match within 1% of known values
|
||||
abs(CDB_Kurtosis(array_agg(val)) + 1.20) < 1e-2 As kurtosis,
|
||||
abs(CDB_Skewness(array_agg(val)) - 0) < 1e-2 As skewness
|
||||
FROM dist
|
Loading…
Reference in New Issue
Block a user