2.13.2.6 vartest1(Pro)
Brief Information
Chi-squared variance test
Additional Information
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;
X-Function Execution Options
Please refer to the page for additional option switches when accessing the x-function from script
Variables
Display Name
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Variable Name
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I/O and Type
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Default Value
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Description
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Input
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irng
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Input
Range
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<active>
|
Specify the input data range
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Test Variance
|
var
|
Input
double
|
1
|
The hypothetical variance value
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Tail
|
tail
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Input
int
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two
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Alternative hypothesis specified by the tail. (Suppose S is the test variance.)
Option list
- H0: Variance <> S
- Tow tailed test to determine if the sample variance is different from the given hypothetical variance
- H0: Variance > S
- Upper tailed test to determine if the sample variance is larger than the given hypothetical variance
- H0: Variance < S
- Lower tailed test to determine if the sample variance is less than the given hypothetical variance
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Significance Level
|
alpha
|
Input
double
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0.05
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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
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P-value
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prob
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Output
double
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<unassigned>
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Associated p-value of the test. If the p-value is less than the value of alpha, the null hypothesis should be rejected
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Lower Confidence Limit
|
lcl
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Output
double
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<unassigned>
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Lower confidence limit of sample variance
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Upper Confidence Limit
|
ucl
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Output
double
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<unassigned>
|
Upper confidence limit of sample variance
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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.
Related X-Functions
vartest2, ttest2, ttest1
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