SAP HANA Predictive Analysis Library (PAL)

3.7.2 Chi-Squared Test for Independent
The chi-squared test for independent tells whether observations of two variables are independent from each
other.
The chi-squared value is defined as:
where O i,j is an observed frequency and E i,j is an expected frequency. Then X 2 will be used to calculate a p-value
by comparing the value of chi-squared to a chi-squared distribution. The degree of freedom is set to
(r-1)*(c-1).
Prerequisites
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The input data contains an ID column in the first column with the type of integer, varchar, or nvarchar and
the other columns are of integer or double data type.
The input data does not contain null value. The algorithm will issue errors when encountering null values.
CHISQTESTIND
This function does the Pearson’s chi-squared test for independent according to the user’s input.
Procedure Generation
CALL SYS.AFLLANG_WRAPPER_PROCEDURE_CREATE (‘AFLPAL’, ‘CHISQTESTIND’,
‘’, '', );
The signature table should contain the following records:
Table 368:
Position Schema Name Table Type Name Parameter Type
1 IN
2 IN
3
4
OUT
OUT
Procedure Calling
CALL . (, ,
, ) with overview;
SAP HANA Predictive Analysis Library (PAL)
PAL Functions P U B L I C 497