SAP HANA Predictive Analysis Library (PAL)

3.7.1 Chi-Squared Test for Goodness of Fit
The chi-squared test for goodness of fit tells whether or not an observed distribution differs from an expected
chi-squared distribution.
The chi-squared value is defined as:
where O i is an observed frequency and E i is an expected frequency.
The chi-squared value X 2 will be used to calculate a p-value by comparing the value of chi-squared to a chisquared
distribution. The degree of freedom is set to n-p where p is the reduction in degrees of freedom.
Prerequisites
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The input data has three columns. The first column is ID column with integer, varchar, or nvarchar type;
the second column is the observed data with integer or double type; the third column is the expected
frequency.
The input data does not contain null value. The algorithm will issue errors when encountering null values.
CHISQTESTFIT
This function does the Pearson’s chi-squared test for goodness of fit according to the user’s input.
Procedure Generation
CALL SYS.AFLLANG_WRAPPER_PROCEDURE_CREATE (‘AFLPAL’, ‘CHISQTESTFIT’,
‘’, '', );
The signature table should contain the following records:
Table 365:
Position Schema Name Table Type Name Parameter Type
1 IN
2
3
OUT
OUT
Procedure Calling
CALL . (, ,
) with overview;
494 P U B L I C
SAP HANA Predictive Analysis Library (PAL)
PAL Functions