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test-t

version 2.0.0.0 (39.1 KB) by Giuseppe Cardillo
Calculate the Student t Test for unequal or equal samples size, unpaired or paired samples.

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Updated 31 Mar 2018

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Student's t test for unpaired or paired samples.
This file is applicable for equal or unequal sample sizes; for paired or
unpaired samples. When the test is unpaired, the Fisher-Snedecor F-test is
performed to assess the equality of variance. If variances are not equal,
Satterthwaite's approximate t test is performed.
Syntax: TESTT(X1,X2,TST,ALPHA,TAIL)

Inputs:
X1 and X2 - data vectors (mandatory).
TST - unpaired (0) or paired (1) test (default = 0).
ALPHA - significance level (default = 0.05).
TAIL - 1-tailed test (1) or 2-tailed test (2). (default = 1).
Outputs:
- t value.
- degrees of freedom.
- Confidence interval of means difference (for paired test)
- p-value
- Power
Example:
X1=[77 79 79 80 80 81 81 81 81 82 82 82 82 83 83 84 84 84 84 85 ...
85 86 86 87 87];

X2=[82 82 83 84 84 85 85 86 86 86 86 86 86 86 86 86 87 87 87 88 ...
88 88 89 90 90];

Calling on Matlab the function: testt

Answer is:

FISHER-SNEDECOR F-TEST FOR EQUALITY OF VARIANCES

F DF_numerator DF_denominator p_value
______ ____________ ______________ _______

1.5379 24 24 0.29861

--------------------------------------------------------------------------------
Variances are equal
--------------------------------------------------------------------------------

STUDENT'S T-TEST FOR UNPAIRED SAMPLES

t DF tail p_value Power
______ __ ____ _________ _______

5.2411 48 1 1.765e-06 0.99958

STATS=TESTT(...) returns a structure with all test(s) statistics

Created by Giuseppe Cardillo
giuseppe.cardillo-edta@poste.it

To cite this file, this would be an appropriate format:
Cardillo G. (2006). Student t-Test for unpaired or paired samples.
http://www.mathworks.com/matlabcentral/fileexchange/12699

Cite As

Giuseppe Cardillo (2020). test-t (https://github.com/dnafinder/testt), GitHub. Retrieved .

Comments and Ratings (11)

Shafa-At Sheikh

How this is different from ttest2 provided by MATLAB?

Nora Heinzelmann

I do not have the Statistics and Machine Learning Toolbox, so I tried this. Turns out it uses 'fcdf', which requires the same toolbox. Oh well...

Jessica Munyan

Can this work for a one-sample t-test? If so, what do you input for x2?

Ben

Thanks

john Chandler

can the p-value, etc be passed onto variables?

Giuseppe Cardillo

You have partially right. I have fixed the bug and uploaded the new file. Thank you very much!

Rune W Berg

There's a small bug in the procedure that prevents you chose 2-tailed test. Its in line 109.

As far as i can see you need to change it to:

109: if tail ~= 0 && tail ~= 1 && tail ~= 2 %check if tst is 0 or 1 or 2

shiva keihaninejad

this m file is good,easy and useful.many thanks Giuseppe

Diego García Bascuñán

If you get the powerStudent, testt works. It's fantastic do it so easily!!!

Giuseppe Cardillo

The file powerStudent is not included because is not a file of mine. As highlighted in the File Details this is a file of Antonio Trujillo Ortiz (file ID: 2907) that you can download.

ifan lin

This m file calls another function: powerStudent, which is not included.

MATLAB Release Compatibility
Created with R2014b
Compatible with any release
Platform Compatibility
Windows macOS Linux

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