added gaussian.awk based on hamming script;

added pwr(x,p) function to sterling_approx;
minor clean up all around;

1 files changed, 21 insertions, 12 deletions

diff --git a/hamming.awk b/hamming.awk
index 95f1cde..fd6d89c 100644
--- a/hamming.awk
+++ b/hamming.awk
@@ -6,25 +6,34 @@
 # 'a0' and 'a1' parameters of the raised cosine.

 

 BEGIN {

+

+    ### R.W. Hamming, "Digital Filters"

+    # H = "0.23 0.54 0.23"

+

     N = ARGV[1]

-    pi = 4*(4*atan2(1,5) - atan2(1,239))

+    # window interval goes from -M to M

+    M = 0.5*(N - 1)

+    pi = 4*atan2(1,1)

 

-    #a0 = (25.0/46.0)

-    #a1 = (21.0/46.0)

+    a0 = (25.0/46.0)

+    a1 = (21.0/46.0)

 

     ### optimal values for equal-ripple

-    a0 = 0.53836

-    a1 = 0.46164

+    #a0 = 0.53836

+    #a1 = 0.46164

 

-    ### R.W. Hamming, "Digital Filters"

-    # H = "0.23 0.54 0.23"

+    ### VonHann

+    #a0 = 0.5

+    #a1 = 0.5

 

-    for (n=0; n<N; n++) {

-        if (N > 1) {

-            w[n] = a0 - a1*cos((2*pi*n)/(N - 1))

-            sum_w += w[n]

+    for (n=-M; n<=M; n++) {

+        if (N > 1 && M > 0) {

+            w[n] = a0 + a1*cos((pi*n)/M)

+            print n, w[n]/M

+        }

+        else {

+            print n, 1.0

         }

-        print 2.0*(w[n])/(N + 1)

     }

 

 }