Initial commit

2016-02-03 18:52:05 +00:00
commit d40505e161
507 changed files with 91383 additions and 0 deletions
@@ -0,0 +1,71 @@
+      SUBROUTINE frenel(x,s,c)
+      INTEGER MAXIT
+      REAL c,s,x,EPS,FPMIN,PI,PIBY2,XMIN
+      PARAMETER (EPS=6.e-8,MAXIT=100,FPMIN=1.e-30,XMIN=1.5,PI=3.1415927,
+     *PIBY2=1.5707963)
+      INTEGER k,n
+      REAL a,absc,ax,fact,pix2,sign,sum,sumc,sums,term,test
+      COMPLEX b,cc,d,h,del,cs
+      LOGICAL odd
+      absc(h)=abs(real(h))+abs(aimag(h))
+      ax=abs(x)
+      if(ax.lt.sqrt(FPMIN))then
+        s=0.
+        c=ax
+      else if(ax.le.XMIN)then
+        sum=0.
+        sums=0.
+        sumc=ax
+        sign=1.
+        fact=PIBY2*ax*ax
+        odd=.true.
+        term=ax
+        n=3
+        do 11 k=1,MAXIT
+          term=term*fact/k
+          sum=sum+sign*term/n
+          test=abs(sum)*EPS
+          if(odd)then
+            sign=-sign
+            sums=sum
+            sum=sumc
+          else
+            sumc=sum
+            sum=sums
+          endif
+          if(term.lt.test)goto 1
+          odd=.not.odd
+          n=n+2
+11      continue
+        pause 'series failed in frenel'
+1       s=sums
+        c=sumc
+      else
+        pix2=PI*ax*ax
+        b=cmplx(1.,-pix2)
+        cc=1./FPMIN
+        d=1./b
+        h=d
+        n=-1
+        do 12 k=2,MAXIT
+          n=n+2
+          a=-n*(n+1)
+          b=b+4.
+          d=1./(a*d+b)
+          cc=b+a/cc
+          del=cc*d
+          h=h*del
+          if(absc(del-1.).lt.EPS)goto 2
+12      continue
+        pause 'cf failed in frenel'
+2       h=h*cmplx(ax,-ax)
+        cs=cmplx(.5,.5)*(1.-cmplx(cos(.5*pix2),sin(.5*pix2))*h)
+        c=real(cs)
+        s=aimag(cs)
+      endif
+      if(x.lt.0.)then
+        c=-c
+        s=-s
+      endif
+      return
+      END