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20 lines
454 B
Fortran
20 lines
454 B
Fortran
subroutine lpf1(data,n,nz)
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C Half-band lowpass filter and decimate by 2.
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real data(n)
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nz=n/2 -10
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do i=1,nz
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j=2*i+8
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data(i)=0.047579*(data(j-9)+data(j+9))
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+ - 0.073227*(data(j-7)+data(j+7))
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+ + 0.113449*(data(j-5)+data(j+5))
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+ - 0.204613*(data(j-3)+data(j+3))
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+ + 0.633339*(data(j-1)+data(j+1))
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+ + data(j)
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enddo
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return
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end
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