Hypothesis-Test Mode Example 2: Normality Tests with GroupByColumns - Teradata Vantage

This example shows the use of grouping columns, and also illustrates the syntax for testing against multiple distributions in a single SQL command.

Input

The input table, factory_7, represents hypothetical mean-time-to-failure data for two products. This is a subset of the rows:

SQL Call

The function call evaluates two possible distributions (normal and uniform) and applies the Kolmogorov-Smirnov (KS) and Anderson-Darling (AD) fit tests.

SELECT * FROM DistributionMatchReduce (
  ON DistributionMatchMultiInput (
	ON (
      SELECT RANK() OVER (PARTITION BY product ORDER BY mttf) AS "rank", product, mttf
	  FROM factory_7 
	  WHERE mttf IS NOT NULL
    ) AS "input" PARTITION BY ANY
	ON (
      SELECT product, COUNT(*) AS group_size 
	  FROM factory_7 
	  WHERE mttf IS NOT NULL 
	  GROUP BY product
    ) AS groupstats DIMENSION
	USING
	ValueColumn ('mttf')
	Tests ('KS', 'AD')
	Distributions ('NORMAL:10000,150','UNIFORMCONTINUOUS:9500,10500')
	GroupByColumns ('product')
	MinGroupSize (50)
  ) PARTITION BY product
) AS dt;

Output