Initial commit

2016-02-03 18:52:05 +00:00
commit d40505e161
507 changed files with 91383 additions and 0 deletions
@@ -0,0 +1,37 @@
+      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).lt.FPMIN)d=FPMIN
+      d=1./d
+      h=d
+      do 11 m=1,MAXIT
+        m2=2*m
+        aa=m*(b-m)*x/((qam+m2)*(a+m2))
+        d=1.+aa*d
+        if(abs(d).lt.FPMIN)d=FPMIN
+        c=1.+aa/c
+        if(abs(c).lt.FPMIN)c=FPMIN
+        d=1./d
+        h=h*d*c
+        aa=-(a+m)*(qab+m)*x/((a+m2)*(qap+m2))
+        d=1.+aa*d
+        if(abs(d).lt.FPMIN)d=FPMIN
+        c=1.+aa/c
+        if(abs(c).lt.FPMIN)c=FPMIN
+        d=1./d
+        del=d*c
+        h=h*del
+        if(abs(del-1.).lt.EPS)goto 1
+11    continue
+      pause 'a or b too big, or MAXIT too small in betacf'
+1     betacf=h
+      return
+      END