Initial Commit

2018-02-08 21:28:33 -05:00
commit 678c1d3966
14352 changed files with 3176737 additions and 0 deletions
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+subroutine fil6521(c1,n1,c2,n2)
+
+! FIR lowpass filter designed using ScopeFIR
+
+!                  Pass #1   Pass #2  
+! -----------------------------------------------
+! fsample    (Hz)  1378.125   Input sample rate
+! Ntaps            21         Number of filter taps
+! fc         (Hz)  40         Cutoff frequency
+! fstop      (Hz)  172.266    Lower limit of stopband
+! Ripple     (dB)  0.1        Ripple in passband
+! Stop Atten (dB)  38         Stopband attenuation
+! fout       (Hz)  344.531    Output sample rate
+
+  parameter (NTAPS=21)
+  parameter (NH=NTAPS/2)
+  parameter (NDOWN=4)                !Downsample ratio = 1/4
+  complex c1(n1)
+  complex c2(n1/NDOWN)
+
+! Filter coefficients:
+  real a(-NH:NH+NTAPS/3)
+  data a/                                                                &
+       -0.011958606980,-0.013888627387,-0.015601306443,-0.010602249570,  &
+        0.003804023436, 0.028320058273, 0.060903935217, 0.096841904411,  &
+        0.129639871228, 0.152644580853, 0.160917511283, 0.152644580853,  &
+        0.129639871228, 0.096841904411, 0.060903935217, 0.028320058273,  &
+        0.003804023436,-0.010602249570,-0.015601306443,-0.013888627387,  &
+        -0.011958606980,1.43370769e-019,2.64031087e-006,6.25548654e+028, &
+        2.44565251e+020,4.74227538e+030,10497312.0e0000,7.74079654e-039/
+
+  n2=(n1-NTAPS+NDOWN)/NDOWN
+  k0=NH-NDOWN+1
+
+! Loop over all output samples
+  do i=1,n2
+     c2(i)=0.
+     k=k0 + NDOWN*i
+     do j=-NH,NH
+        c2(i)=c2(i) + c1(j+k)*a(j)
+     enddo
+  enddo
+
+  return
+end subroutine fil6521