# 2.13.2.6 vartest1(Pro)

## Brief Information

Chi-squared variance test

This feature is for OriginPro only.

Minimum Origin Version Required: 8.0 SR4

## Command Line Usage

 

1. vartest1 irng:=Col(A); 

2. vartest1 irng:=Col(A) var:=2.0 tail:=2; 

3. vartest1 irng:=Col(A) var:=2.0 alpha:=0.05; 

4. vartest1 irng:=Col(A) var:=2.0 prob:=p; 

## Variables

Display
Name
Variable
Name
I/O
and
Type
Default
Value
Description
Input irng

Input

Range

<active>

Specify the input data range

Test Variance var

Input

double

1

The hypothetical variance value

Tail tail

Input

int

two

Alternative hypothesis specified by the tail. (Suppose S is the test variance.)

Option list

• two:Two Tailed
H0: Variance <> S
Tow tailed test to determine if the sample variance is different from the given hypothetical variance
• upper:Upper Tailed
H0: Variance > S
Upper tailed test to determine if the sample variance is larger than the given hypothetical variance
• lower:Lower Tailed
H0: Variance < S
Lower tailed test to determine if the sample variance is less than the given hypothetical variance
Significance Level alpha

Input

double

0.05

Set the significance level of the test

Statistics stat

Output

double

<unassigned>

Value of the F-test statistic

Degrees of Freedom df

Output

double

<unassigned>

Degrees of freedom of the F-test

P-value prob

Output

double

<unassigned>

Associated p-value of the test. If the p-value is less than the value of alpha, the null hypothesis should be rejected

Lower Confidence Limit lcl

Output

double

<unassigned>

Lower confidence limit of sample variance

Upper Confidence Limit ucl

Output

double

<unassigned>

Upper confidence limit of sample variance

## Description

This function performs a chi-squared variance test, to determine whether or not the sample from a normal distribution could have a given hypothetical variance value.

This function is script accessing only, and the test is the same as One Sample Test for Variance on the menu.

## Examples

1. Import vartest1.dat on the \Sample\Statistics\ folder.

2. Use the default setting, type:

vartest1 irng:=Col(A)

3. If you want to know if the variance of the data is equal to a specified value, e.g. 0.015, you can use the command:

vartest1 irng:=Col(A) var:=0.015

## Algorithm

This function is used to perform one sample test for variance from LabTalk Script. Please refer to Algorithm of One-Sample Test for Variance for the detail algorithms.

## References

Snedecor, George W. and Cochran, William G. (1989), Statistical Methods, Eighth Edition, Iowa State University Press.