diff options
| author | Tom Rondeau <tom@trondeau.com> | 2013-11-05 13:52:40 -0500 |
|---|---|---|
| committer | Tom Rondeau <tom@trondeau.com> | 2013-11-05 14:12:38 -0500 |
| commit | 10be863fab34d9d2ca8a080b623e48f4cac0df48 (patch) | |
| tree | 514dc7e3197f7a56fd8fa734685f70afefc83949 /gr-fft/python/fft | |
| parent | 466c218e78b8a566bb8e6eb5ed33f95a3409eb29 (diff) | |
fft: Moved all window building functions into C++.
Remove window.py. All windows built using C++ functions. Exported into Python in same module (from gnuradio.fft import window).
Removed all window building work in firdes, too. firdes.window now makes a direct call to fft.window.build with same parameters.
Added documentation for window functions, including references to where to find coefficients and equations for (most of) the windows.
All changes should not affect existing code.
f
Diffstat (limited to 'gr-fft/python/fft')
| -rw-r--r-- | gr-fft/python/fft/CMakeLists.txt | 1 | ||||
| -rw-r--r-- | gr-fft/python/fft/__init__.py | 2 | ||||
| -rw-r--r-- | gr-fft/python/fft/window.py | 179 |
3 files changed, 0 insertions, 182 deletions
diff --git a/gr-fft/python/fft/CMakeLists.txt b/gr-fft/python/fft/CMakeLists.txt index 33d37b51b9..e0bc19124d 100644 --- a/gr-fft/python/fft/CMakeLists.txt +++ b/gr-fft/python/fft/CMakeLists.txt @@ -24,7 +24,6 @@ GR_PYTHON_INSTALL( FILES __init__.py logpwrfft.py - window.py DESTINATION ${GR_PYTHON_DIR}/gnuradio/fft COMPONENT "fft_python" ) diff --git a/gr-fft/python/fft/__init__.py b/gr-fft/python/fft/__init__.py index e0803cbf38..1864353ed1 100644 --- a/gr-fft/python/fft/__init__.py +++ b/gr-fft/python/fft/__init__.py @@ -30,5 +30,3 @@ except ImportError: dirname, filename = os.path.split(os.path.abspath(__file__)) __path__.append(os.path.join(dirname, "..", "..", "swig")) from fft_swig import * - -from window import * diff --git a/gr-fft/python/fft/window.py b/gr-fft/python/fft/window.py deleted file mode 100644 index 0065a08a61..0000000000 --- a/gr-fft/python/fft/window.py +++ /dev/null @@ -1,179 +0,0 @@ -# -# Copyright 2004,2005,2009 Free Software Foundation, Inc. -# -# This file is part of GNU Radio -# -# GNU Radio is free software; you can redistribute it and/or modify -# it under the terms of the GNU General Public License as published by -# the Free Software Foundation; either version 3, or (at your option) -# any later version. -# -# GNU Radio is distributed in the hope that it will be useful, -# but WITHOUT ANY WARRANTY; without even the implied warranty of -# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -# GNU General Public License for more details. -# -# You should have received a copy of the GNU General Public License -# along with GNU Radio; see the file COPYING. If not, write to -# the Free Software Foundation, Inc., 51 Franklin Street, -# Boston, MA 02110-1301, USA. -# - -''' -Routines for designing window functions. -''' - -import math - -def izero(x): - izeroepsilon = 1e-21 - halfx = x/2.0 - accum = u = n = 1 - while 1: - temp = halfx/n - n += 1 - temp *= temp - u *= temp - accum += u - if u >= IzeroEPSILON*sum: - break - return accum - -def midm1(fft_size): - return (fft_size - 1)/2 - -def midp1(fft_size): - return (fft_size+1)/2 - -def freq(fft_size): - return 2.0*math.pi/fft_size - -def rate(fft_size): - return 1.0/(fft_size >> 1) - -def expn(fft_size): - math.log(2.0)/(midn(fft_size) + 1.0) - -def hamming(fft_size): - window = [] - for index in xrange(fft_size): - window.append(0.54 - 0.46 * math.cos (2 * math.pi / fft_size * index)) # Hamming window - return window - -def hanning(fft_size): - window = [] - for index in xrange(fft_size): - window.append(0.5 - 0.5 * math.cos (2 * math.pi / fft_size * index)) # von Hann window - return window - -def welch(fft_size): - window = [0 for i in range(fft_size)] - j = fft_size-1 - for index in xrange(midn(fft_size)+1): - window[j] = window[index] = (1.0 - math.sqrt((index - midm1(fft_size)) / midp1(fft_size))) - j -= 1 - return window - -def parzen(fft_size): - window = [0 for i in range(fft_size)] - j = fft_size-1 - for index in xrange(midn(fft_size)+1): - window[j] = window[index] = (1.0 - math.abs((index - midm1(fft_size)) / midp1(fft_size))) - j -= 1 - return window - -def bartlett(fft_size): - mfrq = freq(fft_size) - angle = 0 - window = [0 for i in range(fft_size)] - j = fft_size-1 - for index in xrange(midn(fft_size)+1): - window[j] = window[index] = angle - angle += freq - j -= 1 - return window - -def blackman2(fft_size): - mfrq = freq(fft_size) - angle = 0 - window = [0 for i in range(fft_size)] - j = fft_size-1 - for index in xrange(midn(fft_size)+1): - cx = math.cos(angle) - window[j] = window[index] = (.34401 + (cx * (-.49755 + (cx * .15844)))) - angle += freq - j -= 1 - return window - -def blackman3(fft_size): - mfrq = freq(fft_size) - angle = 0 - window = [0 for i in range(fft_size)] - j = fft_size-1 - for index in xrange(midn(fft_size)+1): - cx = math.cos(angle) - window[j] = window[index] = (.21747 + (cx * (-.45325 + (cx * (.28256 - (cx * .04672)))))) - angle += freq - j -= 1 - return window - -def blackman4(fft_size): - mfrq = freq(fft_size) - angle = 0 - window = [0 for i in range(fft_size)] - j = fft_size-1 - for index in xrange(midn(fft_size)+1): - cx = math.cos(angle) - window[j] = window[index] = (.084037 + (cx * (-.29145 + (cx * (.375696 + (cx * (-.20762 + (cx * .041194)))))))) - angle += freq - j -= 1 - return window - -def exponential(fft_size): - expsum = 1.0 - window = [0 for i in range(fft_size)] - j = fft_size-1 - for index in xrange(midn(fft_size)+1): - window[j] = window[i] = (expsum - 1.0) - expsum *= expn(fft_size) - j -= 1 - return window - -def riemann(fft_size): - sr1 = freq(fft_size) - window = [0 for i in range(fft_size)] - j = fft_size-1 - for index in xrange(midn(fft_size)): - if index == midn(fft_size): - window[index] = window[j] = 1.0 - else: - cx = sr1*midn(fft_size) - index - window[index] = window[j] = math.sin(cx)/cx - j -= 1 - return window - -def kaiser(fft_size,beta): - ibeta = 1.0/izero(beta) - inm1 = 1.0/(fft_size) - window = [0 for i in range(fft_size)] - for index in xrange(fft_size): - 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 |