mirror of https://github.com/saitohirga/WSJT-X.git
24 lines
538 B
Fortran
24 lines
538 B
Fortran
subroutine hipass(y,npts,nwidth)
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! Hipass filter for time-domain data. Removes an RC-type running
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! mean (time constant nwidth) from array y(1:npts).
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real y(npts)
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c1=1.0/nwidth
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c2=1.0-c1
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s=0.
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do i=1,nwidth !Get initial average
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s=s+y(i)
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enddo
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ave=c1*s
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do i=1,npts !Do the filtering
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y0=y(i)
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y(i)=y0-ave !Remove the mean
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ave=c1*y0 + c2*ave !Update the mean
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enddo
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return
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end subroutine hipass
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