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MyFisher23

22 Jun 2007 (Updated 23 Oct 2009)

A very compact routine for Fisher's exact test on 2x3 contingency table

File Information
Description	Fisher's exact test of 2x3 contingency tables permits calculation of precise probabilities in situation where, as a consequence of small cell frequencies, the much more rapid normal approximation and chi-square calculations are liable to be inaccurate. The Fisher's exact test involves the computations of several factorials to obtain the probability of the observed and each of the more extreme tables. Factorials growth quickly, so it's necessary use logarithms of factorials. This computations is very easy in Matlab because x!=gamma(x+1) and log(x!)=gammaln(x+1). This function is now fully vectorized to speed up the computation.
MATLAB release	MATLAB 7.3 (R2006b)
Zip File Content
Other Files	license.txt, myfisher23.m

Tags for This File
Everyone's Tags	fishers exact test 2x3 matrix, probability(2), statistics(2)
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Comments and Ratings (1)
07 May 2008	Shilpa Gandhi	Fast, provides good output display. Exactly what I needed. Thanks!

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Updates
26 Jun 2007	Bug fixed in 1-tailed P calculation
02 Jul 2007	More compact and vectorized function
01 May 2008	waitbar added
18 Jun 2008	Speeding up using gammaln function and vectorization.
12 Nov 2008	Changes in help section
25 Nov 2008	little improvements in tables enumeration
23 Oct 2009	Actually, the function also computes the mid-P correction to make the test less conservative.
23 Oct 2009	Actually, the function also computes the mid-P correction to make the test less conservative.

Tag Activity for this File
Tag	Applied By	Date/Time
statistics	Giuseppe Cardillo	22 Oct 2008 09:16:52
probability	Giuseppe Cardillo	22 Oct 2008 09:16:52
fishers exact test 2x3 matrix	Giuseppe Cardillo	22 Oct 2008 09:16:52
statistics	Cristina McIntire	12 Nov 2008 14:02:19
probability	Cristina McIntire	12 Nov 2008 14:02:19

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