mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-13 23:51:49 -05:00
27 lines
550 B
Fortran
27 lines
550 B
Fortran
|
subroutine twkfreq1(ca,npts,fsample,a,cb)
|
||
|
|
|
||
|
|
complex ca(npts)
|
||
|
|
complex cb(npts)
|
||
|
|
complex w,wstep
|
||
|
|
real a(5)
|
||
|
|
data twopi/6.283185307/
|
||
|
|
|
||
|
|
! Mix the complex signal
|
||
|
|
w=1.0
|
||
|
|
wstep=1.0
|
||
|
|
x0=0.5*(npts+1)
|
||
|
|
s=2.0/npts
|
||
|
|
do i=1,npts
|
||
|
|
x=s*(i-x0)
|
||
|
|
p2=1.5*x*x - 0.5
|
||
|
|
p3=2.5*(x**3) - 1.5*x
|
||
|
|
p4=4.375*(x**4) - 3.75*(x**2) + 0.375
|
||
|
|
dphi=(a(1) + x*a(2) + p2*a(3) + p3*a(4) + p4*a(5)) * (twopi/fsample)
|
||
|
|
wstep=cmplx(cos(dphi),sin(dphi))
|
||
|
|
w=w*wstep
|
||
|
|
cb(i)=w*ca(i)
|
||
|
|
enddo
|
||
|
|
|
||
|
|
return
|
||
|
|
end subroutine twkfreq1
|