1 files changed, 3 insertions, 3 deletions
diff --git a/fir_window.awk b/fir_window.awk
index 076e5df..d5ad86c 100644
--- a/fir_window.awk
+++ b/fir_window.awk
@@ -1,7 +1,7 @@
 #!/usr/bin/awk -f
 
-### hamming.awk
-# generate a Hamming window
+### fir_window.awk
+# generate a FIR window
 # R.W. Hamming, 'Digital Filters': H = '0.23 0.54 0.23'
 # https://en.wikipedia.org/wiki/Window_function provides a few values for the
 # 'a0' and 'a1' parameters of the raised cosine.
@@ -43,7 +43,7 @@ BEGIN {
 
     # window interval goes from -M to M
     M = 0.5*(N - 1)
-    pi = 4*atan2(1,1)
+    pi = 4.0*atan2(1.0, 1.0)
 
     for (n=-M; n<=M; n++) {
         if (N > 1 && M > 0) {