forum.alglib.net
http://forum.alglib.net/

Fisher F test code and algorithm?
http://forum.alglib.net/viewtopic.php?f=2&t=3764		 Page 1 of 1
Author:  Tester1 [ Mon Jul 18, 2016 12:11 pm ]
Post subject:  Fisher F test code and algorithm?
Hello
I have questions regarding this part of the code in the file variancetests.c
for Fisher's F-test:
This is the final part of the code for the test itself.

df1 = n-1;
df2 = m-1;
stat = ae_minreal(xvar/yvar, yvar/xvar, _state);
*bothtails = 1-(fdistribution(df1, df2, 1/stat, _state)-fdistribution(df1, df2, stat, _state));
*lefttail = fdistribution(df1, df2, xvar/yvar, _state);
*righttail = 1-(*lefttail);

Could you please give insights on the following points:
1) in *lefttail = fdistribution(df1, df2, xvar/yvar, _state);
shouldn't xvar/yvar be replaced by stat?
2) I am not much literate in C, but I could not find "ae_minreal" as a function (I googled and searched the source files), I suppose that it is a function that discriminate which of both inputs is the greatest. Am I right?
3) I don't really understand the bothtail formula. Shouldn't it be lefttail-righttail? (hence 2*leftail-1)?

Thanks by advance
Page 1 of 1 All times are UTC
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
http://www.phpbb.com/