Merge branch 'flattopwindow' of http://gnuradio.org/git/jblum

Merge-fix: Remove debugging print
Merge-fix: Update copyrights

* 'flattopwindow' of http://gnuradio.org/git/jblum:
  Added window option to wxgui fft and waterfall sink.
  redid cos windows, added flattop and nuttall_cfd

2 files changed, 22 insertions, 30 deletions

diff --git a/gnuradio-core/src/python/gnuradio/blks2impl/logpwrfft.py b/gnuradio-core/src/python/gnuradio/blks2impl/logpwrfft.py
index 7ef40be40..200c4cfbe 100644
--- a/gnuradio-core/src/python/gnuradio/blks2impl/logpwrfft.py
+++ b/gnuradio-core/src/python/gnuradio/blks2impl/logpwrfft.py
@@ -28,7 +28,7 @@ class _logpwrfft_base(gr.hier_block2):
     Create a log10(abs(fft)) stream chain, with real or complex input.
     """
 
-    def __init__(self, sample_rate, fft_size, ref_scale, frame_rate, avg_alpha, average):
+    def __init__(self, sample_rate, fft_size, ref_scale, frame_rate, avg_alpha, average, win=None):
         """
         Create an log10(abs(fft)) stream chain.
         Provide access to the setting the filter and sample rate.
@@ -38,6 +38,7 @@ class _logpwrfft_base(gr.hier_block2):
         @param frame_rate        Output frame rate
         @param avg_alpha        FFT averaging (over time) constant [0.0-1.0]
         @param average                Whether to average [True, False]
+        @param win              the window taps generation function
         """
         gr.hier_block2.__init__(self, self._name,
                                 gr.io_signature(1, 1, self._item_size),          # Input signature
@@ -48,7 +49,8 @@ class _logpwrfft_base(gr.hier_block2):
                                               vec_rate=frame_rate,
                                               vec_len=fft_size)
 
-        fft_window = window.blackmanharris(fft_size)
+        if win is None: win = window.blackmanharris
+        fft_window = win(fft_size)
         fft = self._fft_block[0](fft_size, True, fft_window)
         window_power = sum(map(lambda x: x*x, fft_window))
 
diff --git a/gnuradio-core/src/python/gnuradio/window.py b/gnuradio-core/src/python/gnuradio/window.py
index fb4a10675..e109a9892 100644
--- a/gnuradio-core/src/python/gnuradio/window.py
+++ b/gnuradio-core/src/python/gnuradio/window.py
@@ -1,5 +1,5 @@
 #
-# Copyright 2004,2005 Free Software Foundation, Inc.
+# Copyright 2004,2005,2009 Free Software Foundation, Inc.
 # 
 # This file is part of GNU Radio
 # 
@@ -153,32 +153,6 @@ def riemann(fft_size):
         j -= 1
     return window
 
-def blackmanharris(fft_size):
-    a0 = 0.35875
-    a1 = 0.48829
-    a2 = 0.14128
-    a3 = 0.01168
-    window = [0 for i in range(fft_size)]
-    for index in xrange(fft_size):
-        window[index] = a0 
-        window[index] -= a1*math.cos(2.0*math.pi*(index+0.5)/(fft_size - 1))
-        window[index] += a2*math.cos(4.0*math.pi*(index+0.5)/(fft_size - 1))
-        window[index] -= a3*math.cos(6.0*math.pi*(index+0.5)/(fft_size - 1))
-    return window
-
-def nuttall(fft_size):
-    a0 = 0.3635819
-    a1 = 0.4891775
-    a2 = 0.1365995
-    a3 = 0.0106411
-    window = [0 for i in range(fft_size)]
-    for index in xrange(fft_size):
-        window[index] = a0 
-        window[index] -= a1*math.cos(2.0*math.pi*(index+0.5)/(fft_size - 1))
-        window[index] += a2*math.cos(4.0*math.pi*(index+0.5)/(fft_size - 1))
-        window[index] -= a3*math.cos(6.0*math.pi*(index+0.5)/(fft_size - 1))
-    return window
-
 def kaiser(fft_size,beta):
     ibeta = 1.0/izero(beta)
     inm1 = 1.0/(fft_size)
@@ -187,4 +161,20 @@ def kaiser(fft_size,beta):
         window[index] = izero(beta*math.sqrt(1.0 - (index * inm1)*(index * inm1))) * ibeta
     return window
 
-    
+# Closure to generate functions to create cos windows
+
+def coswindow(coeffs):
+    def closure(fft_size):
+        window = [0] * fft_size
+        #print list(enumerate(coeffs))
+        for w_index in range(fft_size):
+            for (c_index, coeff) in enumerate(coeffs):
+                window[w_index] += (-1)**c_index * coeff * math.cos(2.0*c_index*math.pi*(w_index+0.5)/(fft_size-1))
+        return window
+    return closure
+
+blackmanharris = coswindow((0.35875,0.48829,0.14128,0.01168))
+nuttall = coswindow((0.3635819,0.4891775,0.1365995,0.0106411))  # Wikipedia calls this Blackman-Nuttall
+nuttall_cfd = coswindow((0.355768,0.487396,0.144232,0.012604)) # Wikipedia calls this Nuttall, continuous first deriv
+flattop = coswindow((1.0,1.93,1.29,0.388,0.032)) # Flat top window, coeffs from Wikipedia
+rectangular = lambda fft_size: [1]*fft_size