hanaml.ftest.equal.var is a R wrapper for SAP HANA PAL Equal Variance Test.

hanaml.ftest.equal.var(data.x, data.y, test.type = NULL)

Arguments

data.x

DataFrame
DataFrame containting the attribute data.

data.y

DataFrame
DataFrame containting the attribute data.

test.type

{"two.sides", "less","greater"}, optional
States the type of the alternative hypothesis for the F test. The types are given as follows:

  • "two.sides": The variances are not equal

  • "less":variance from the first population is less than the second population variance

  • "greater":variance from the first population is greater than the second population variance

Defaults to "two.sides".

Value

DataFrame
Statistics, structured as follows:

  • STAT_NAME: Name of statistics.

  • STAT_VALUE: Value of statistics.

Details

This function uses statistical F Test to compare two variances s1 and s2 of two samples by dividing them, i.e. F = s1^2 / s2^2.

Examples

Two input Dataframe:


 > df.x$Collect()
    X
 1  1
 2  2
 3  4
 4  7
 5  3

> df.y$Collect()
      Y
1  10.0
2  15.0
3  12.0

Call the function:


> res <- hanaml.ftest.equal.var(data.x, data.y, test.type="two.sides")

Results:


> res$Collect()
                       STAT_NAME  STAT_VALUE
1                        F Value    0.836842
2    numerator degree of freedom    4.000000
3  denominator degree of freedom    2.000000
4                        p-value    0.783713