1 files changed, 39 insertions, 0 deletions
diff --git a/fir_window_gaussian.awk b/fir_window_gaussian.awk
new file mode 100644
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--- /dev/null
+++ b/fir_window_gaussian.awk
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+#!/usr/bin/awk -f
+
+### fir_window_gaussian.awk
+# generate a Gaussian window
+# https://en.wikipedia.org/wiki/Window_function
+
+
+# Gaussian window
+function gaussian(n) {
+    # sigma <= 0.5
+    sigma = 0.4
+    en[n] = (n - M)/(sigma*M)
+    return exp(-0.5*e[n]*e[n])
+}
+
+
+BEGIN {
+
+    ARGV[1] ? N = ARGV[1] : N = 0
+    ARGV[2] ? OFMT = "%." ARGV[2] "g" : OFMT = "%g"
+
+    # window interval goes from -M to M
+    M = 0.5*(N - 1)
+    pi = 4*atan2(1,1)
+
+    for (n=0; n<N; n++) {
+        if (N > 1 && M > 0) {
+            # sigma <= 0.5
+            sigma = 0.4
+            e[n] = (n - M)/(sigma*M)
+            w[n] = exp(-0.5*e[n]*e[n])
+            print n, w[n]/M
+        }
+        else {
+            print n, 1.0
+        }
+    }
+}
+