|
0
|
1 function [P_VALUE,FLAG_ERR]=comp_nbin_p_value_mean_variance(MEAN1,MEAN2,SIGMA1,SIGMA2,COUNTS1,COUNTS2)
|
|
|
2 %This function computes the p_value for a negative binomial
|
|
|
3 %hypothesis test given the mean and variance of two nbin
|
|
|
4 %distributions and counts from the respective distributions
|
|
|
5
|
|
|
6 FLAG_ERR=0;
|
|
|
7 r1=(MEAN1^2)/(SIGMA1-MEAN1);
|
|
|
8 p1=1-(MEAN1/(SIGMA1));
|
|
|
9 r2=(MEAN2^2)/(SIGMA2-MEAN2);
|
|
|
10 p2=1-(MEAN2/(SIGMA2));
|
|
|
11
|
|
|
12 P_OBS=calcl_nbin_pdf(COUNTS1,r1,1-p1)*calcl_nbin_pdf(COUNTS2,r2,1-p2);
|
|
|
13
|
|
|
14
|
|
|
15 P_A=calcl_nbin_pdf(0:(COUNTS1+COUNTS2),r1,1-p1);
|
|
|
16 P_B=calcl_nbin_pdf((COUNTS1+COUNTS2):(-1):0,r2,1-p2);
|
|
|
17 P_COMB=sort(P_A.*P_B);
|
|
|
18
|
|
|
19 if sum(P_COMB)>0
|
|
|
20 POS= find(P_COMB<=P_OBS,1,'last');
|
|
|
21 if isempty(POS)
|
|
|
22 P_VALUE=min(P_COMB);
|
|
|
23 else
|
|
|
24 P_VALUE=sum(P_COMB(1:POS))/sum(P_COMB);
|
|
|
25 end
|
|
|
26 else
|
|
|
27 P_VALUE=1;
|
|
|
28 end
|
|
|
29
|
|
|
30
|
|
|
31 |
