2015-11-18 01:28:12 +00:00
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program t1
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2016-04-08 15:55:28 +00:00
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parameter (NFFT=1024,NH=NFFT/2)
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real w(-24:24)
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real x(0:NFFT-1)
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complex cx(0:NH)
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equivalence (x,cx)
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! FIR lowpass filter designed using ScopeFIR
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! fsample = 48000 Hz
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! Ntaps = 49
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! fc = 4500 Hz
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! fstop = 6000 Hz
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! Ripple = 1 dB
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! Stop Atten = 40 dB
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! fout = 12000 Hz
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! Filter coefficients:
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data w/ &
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0.000861074040, 0.010051920210, 0.010161983649, 0.011363155076, &
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0.008706594219, 0.002613872664,-0.005202883094,-0.011720748164, &
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-0.013752163325,-0.009431602741, 0.000539063909, 0.012636767098, &
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0.021494659597, 0.021951235065, 0.011564169382,-0.007656470131, &
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-0.028965787341,-0.042637874109,-0.039203309748,-0.013153301537, &
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0.034320769178, 0.094717832646, 0.154224604789, 0.197758325022, &
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0.213715139513, 0.197758325022, 0.154224604789, 0.094717832646, &
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0.034320769178,-0.013153301537,-0.039203309748,-0.042637874109, &
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-0.028965787341,-0.007656470131, 0.011564169382, 0.021951235065, &
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0.021494659597, 0.012636767098, 0.000539063909,-0.009431602741, &
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-0.013752163325,-0.011720748164,-0.005202883094, 0.002613872664, &
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0.008706594219, 0.011363155076, 0.010161983649, 0.010051920210, &
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0.000861074040/
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x=0.
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do i=-24,24
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j=i
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if(j.lt.0) j=j+NFFT
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x(j)=w(i)
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2015-11-18 01:28:12 +00:00
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enddo
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2016-04-08 15:55:28 +00:00
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call four2a(x,NFFT,1,-1,0) !r2c FFT
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2015-11-18 01:28:12 +00:00
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2016-04-08 15:55:28 +00:00
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df=48000.0/NFFT
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do i=0,NH
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y=abs(cx(i))
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s=y*y
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f=i*df
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write(13,1000) f,y,s,db(s),cx(i)
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1000 format(6f12.6)
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2015-11-18 01:28:12 +00:00
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enddo
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2016-04-08 15:55:28 +00:00
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end program t1
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