|
|
【答案】应助回帖
★ ★ ★ ★ ★ ★
jjdg(金币+1): 感谢分享你的解决方案 2011-08-06 15:28:45
dubo(金币+5, 程序强帖+1): good 2011-08-21 14:01:09
已经解决，方案如下，谢谢
FUNCTION betai(a,b,x)
REAL betai,a,b,x
!USES betacf,gammln
REAL bt,betacf,gammln
if(x<0..or.x>1.) pause 'bad argument x in betai'
if(x==0..or.x==1.) then
bt=0.
else
bt=exp(gammln(a+b)-gammln(a)-gammln(b)+a*log(x)&
+b*log(1.-x))
endif
if(x<(a+1.)/(a+b+2.)) then
betai=bt*betacf(a,b,x)/a
return
else
betai=1.-bt*betacf(b,a,1.-x)/b
return
endif
END FUNCTION betai
FUNCTION betacf(a,b,x)
INTEGER maxit
REAL betacf,a,b,x,EPS,fpmin
PARAMETER (maxit=100,EPS=3.e-7,fpmin=1.e-30)
INTEGER m,m2
REAL aa,c,d,del,h,qab,qam,qap
qab=a+b
qap=a+1.
qam=a-1.
c=1.
d=1.-qab*x/qap
if(abs(d)
d=1./d
h=d
do m=1,maxit
m2=2*m
aa=m*(b-m)*x/((qam+m2)*(a+m2))
d=1.+aa*d
if(abs(d)
c=1.+aa/c
if(abs(c)
d=1./d
h=h*d*c
aa=-(a+m)*(qab+m)*x/((a+m2)*(qap+m2))
d=1.+aa*d
if(abs(d)
c=1.+aa/c
if(abs(c)
d=1./d
del=d*c
h=h*del
if(abs(del-1.)
betacf=h
return
end if
end do
pause 'a or b too big, or maxit too small in betacf'
END FUNCTION betacf
FUNCTION gammln(xx)
REAL gammln,xx
INTEGER j
DOUBLE PRECISION ser,stp,tmp,x,y,cof(6)
SAVE cof,stp
DATA cof,stp/76.18009172947146d0,-86.50532032941677d0,&
24.01409824083091d0,-1.231739572450155d0,&
.1208650973866179d-2,-.5395239384953d-5,&
2.5066282746310005d0/
x=xx
y=x
tmp=x+5.5d0
tmp=(x+0.5d0)*log(tmp)-tmp
ser=1.000000000190015d0
do j=1,6
y=y+1.d0
ser=ser+cof(j)/y
end do
gammln=tmp+log(stp*ser/x)
END FUNCTION gammln
program pvalue
REAL df, r, t, prob
df=17-2 ! 17 is sample size
r=0.188446645 ! pearson coefficient
t=(abs(r)*sqrt(df))/sqrt(1-r**2)
prob=betai(0.5*df,0.5,df/(df+t**2))
write (*,*) prob
end program pvalue |
|
回复此楼
点击这里搜索更多相关资源