28 lines
440 B
Plaintext
28 lines
440 B
Plaintext
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subroutine ps4(dat,nfft,s)
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parameter (NMAX=2520+2)
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parameter (NHMAX=NMAX/2-1)
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real dat(nfft)
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real dat2(NMAX)
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real s(NHMAX)
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complex c(0:NMAX)
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equivalence(dat2,c)
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nh=nfft/2
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do i=1,nh
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dat2(i)=dat(i)/128.0 !### Why 128 ??
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enddo
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do i=nh+1,nfft
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dat2(i)=0.
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enddo
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call four2a(c,nfft,1,-1,0)
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fac=1.0/nfft
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do i=1,nh
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s(i)=fac*(real(c(i))**2 + aimag(c(i))**2)
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enddo
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return
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end subroutine ps4
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