Initial commit

dataassim/math/numrec/f77_sources/convlv.for

@@ -0,0 +1,31 @@
+      SUBROUTINE convlv(data,n,respns,m,isign,ans)
+      INTEGER isign,m,n,NMAX
+      REAL data(n),respns(n)
+      COMPLEX ans(n)
+      PARAMETER (NMAX=4096)
+CU    USES realft,twofft
+      INTEGER i,no2
+      COMPLEX fft(NMAX)
+      do 11 i=1,(m-1)/2
+        respns(n+1-i)=respns(m+1-i)
+11    continue
+      do 12 i=(m+3)/2,n-(m-1)/2
+        respns(i)=0.0
+12    continue
+      call twofft(data,respns,fft,ans,n)
+      no2=n/2
+      do 13 i=1,no2+1
+        if (isign.eq.1) then
+          ans(i)=fft(i)*ans(i)/no2
+        else if (isign.eq.-1) then
+          if (abs(ans(i)).eq.0.0) pause
+     *'deconvolving at response zero in convlv'
+          ans(i)=fft(i)/ans(i)/no2
+        else
+          pause 'no meaning for isign in convlv'
+        endif
+13    continue
+      ans(1)=cmplx(real(ans(1)),real(ans(no2+1)))
+      call realft(ans,n,-1)
+      return
+      END