1subroutine tweak1(ca,jz,f0,cb) 2 3! Shift frequency of analytic signal ca, with output to cb 4 5 complex ca(jz),cb(jz) 6 real*8 twopi 7 complex*16 w,wstep 8 complex w4 9 data twopi/0.d0/ 10 save twopi 11 12 if(twopi.eq.0.d0) twopi=8.d0*atan(1.d0) 13 w=1.d0 14 dphi=twopi*f0/12000.d0 15 wstep=cmplx(cos(dphi),sin(dphi)) 16 do i=1,jz 17 w=w*wstep 18 w4=w 19 cb(i)=w4*ca(i) 20 enddo 21 22 return 23end subroutine tweak1 24