diff options
Diffstat (limited to 'gr-utils/src/python/plot_fft_base.py')
| -rwxr-xr-x | gr-utils/src/python/plot_fft_base.py | 249 |
1 files changed, 249 insertions, 0 deletions
diff --git a/gr-utils/src/python/plot_fft_base.py b/gr-utils/src/python/plot_fft_base.py new file mode 100755 index 000000000..0b5df504b --- /dev/null +++ b/gr-utils/src/python/plot_fft_base.py @@ -0,0 +1,249 @@ +#!/usr/bin/env python +# +# Copyright 2007,2008,2011 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. +# + +try: + import scipy + from scipy import fftpack +except ImportError: + print "Please install SciPy to run this script (http://www.scipy.org/)" + raise SystemExit, 1 + +try: + from pylab import * +except ImportError: + print "Please install Matplotlib to run this script (http://matplotlib.sourceforge.net/)" + raise SystemExit, 1 + +from optparse import OptionParser + +class plot_fft_base: + def __init__(self, datatype, filename, options): + self.hfile = open(filename, "r") + self.block_length = options.block + self.start = options.start + self.sample_rate = options.sample_rate + + self.datatype = getattr(scipy, datatype) + self.sizeof_data = self.datatype().nbytes # number of bytes per sample in file + + self.axis_font_size = 16 + self.label_font_size = 18 + self.title_font_size = 20 + self.text_size = 22 + + # Setup PLOT + self.fig = figure(1, figsize=(16, 12), facecolor='w') + rcParams['xtick.labelsize'] = self.axis_font_size + rcParams['ytick.labelsize'] = self.axis_font_size + + self.text_file = figtext(0.10, 0.94, ("File: %s" % filename), weight="heavy", size=self.text_size) + self.text_file_pos = figtext(0.10, 0.88, "File Position: ", weight="heavy", size=self.text_size) + self.text_block = figtext(0.35, 0.88, ("Block Size: %d" % self.block_length), + weight="heavy", size=self.text_size) + self.text_sr = figtext(0.60, 0.88, ("Sample Rate: %.2f" % self.sample_rate), + weight="heavy", size=self.text_size) + self.make_plots() + + self.button_left_axes = self.fig.add_axes([0.45, 0.01, 0.05, 0.05], frameon=True) + self.button_left = Button(self.button_left_axes, "<") + self.button_left_callback = self.button_left.on_clicked(self.button_left_click) + + self.button_right_axes = self.fig.add_axes([0.50, 0.01, 0.05, 0.05], frameon=True) + self.button_right = Button(self.button_right_axes, ">") + self.button_right_callback = self.button_right.on_clicked(self.button_right_click) + + self.xlim = self.sp_iq.get_xlim() + + self.manager = get_current_fig_manager() + connect('draw_event', self.zoom) + connect('key_press_event', self.click) + show() + + def get_data(self): + self.position = self.hfile.tell()/self.sizeof_data + self.text_file_pos.set_text("File Position: %d" % (self.position)) + try: + self.iq = scipy.fromfile(self.hfile, dtype=self.datatype, count=self.block_length) + except MemoryError: + print "End of File" + else: + self.iq_fft = self.dofft(self.iq) + + tstep = 1.0 / self.sample_rate + #self.time = scipy.array([tstep*(self.position + i) for i in xrange(len(self.iq))]) + self.time = scipy.array([tstep*(i) for i in xrange(len(self.iq))]) + + self.freq = self.calc_freq(self.time, self.sample_rate) + + def dofft(self, iq): + N = len(iq) + iq_fft = scipy.fftpack.fftshift(scipy.fft(iq)) # fft and shift axis + iq_fft = 20*scipy.log10(abs((iq_fft+1e-15)/N)) # convert to decibels, adjust power + # adding 1e-15 (-300 dB) to protect against value errors if an item in iq_fft is 0 + return iq_fft + + def calc_freq(self, time, sample_rate): + N = len(time) + Fs = 1.0 / (time.max() - time.min()) + Fn = 0.5 * sample_rate + freq = scipy.array([-Fn + i*Fs for i in xrange(N)]) + return freq + + def make_plots(self): + # if specified on the command-line, set file pointer + self.hfile.seek(self.sizeof_data*self.start, 1) + + # Subplot for real and imaginary parts of signal + self.sp_iq = self.fig.add_subplot(2,2,1, position=[0.075, 0.2, 0.4, 0.6]) + self.sp_iq.set_title(("I&Q"), fontsize=self.title_font_size, fontweight="bold") + self.sp_iq.set_xlabel("Time (s)", fontsize=self.label_font_size, fontweight="bold") + self.sp_iq.set_ylabel("Amplitude (V)", fontsize=self.label_font_size, fontweight="bold") + + # Subplot for FFT plot + self.sp_fft = self.fig.add_subplot(2,2,2, position=[0.575, 0.2, 0.4, 0.6]) + self.sp_fft.set_title(("FFT"), fontsize=self.title_font_size, fontweight="bold") + self.sp_fft.set_xlabel("Frequency (Hz)", fontsize=self.label_font_size, fontweight="bold") + self.sp_fft.set_ylabel("Power Spectrum (dBm)", fontsize=self.label_font_size, fontweight="bold") + + self.get_data() + + self.plot_iq = self.sp_iq.plot([], 'bo-') # make plot for reals + self.plot_iq += self.sp_iq.plot([], 'ro-') # make plot for imags + self.draw_time() # draw the plot + + self.plot_fft = self.sp_fft.plot([], 'bo-') # make plot for FFT + self.draw_fft() # draw the plot + + draw() + + def draw_time(self): + reals = self.iq.real + imags = self.iq.imag + self.plot_iq[0].set_data([self.time, reals]) + self.plot_iq[1].set_data([self.time, imags]) + self.sp_iq.set_xlim(self.time.min(), self.time.max()) + self.sp_iq.set_ylim([1.5*min([reals.min(), imags.min()]), + 1.5*max([reals.max(), imags.max()])]) + + def draw_fft(self): + self.plot_fft[0].set_data([self.freq, self.iq_fft]) + self.sp_fft.set_xlim(self.freq.min(), self.freq.max()) + self.sp_fft.set_ylim([self.iq_fft.min()-10, self.iq_fft.max()+10]) + + def update_plots(self): + self.draw_time() + self.draw_fft() + + self.xlim = self.sp_iq.get_xlim() + draw() + + def zoom(self, event): + newxlim = scipy.array(self.sp_iq.get_xlim()) + curxlim = scipy.array(self.xlim) + if(newxlim[0] != curxlim[0] or newxlim[1] != curxlim[1]): + self.xlim = newxlim + #xmin = max(0, int(ceil(self.sample_rate*(self.xlim[0] - self.position)))) + #xmax = min(int(ceil(self.sample_rate*(self.xlim[1] - self.position))), len(self.iq)) + xmin = max(0, int(ceil(self.sample_rate*(self.xlim[0])))) + xmax = min(int(ceil(self.sample_rate*(self.xlim[1]))), len(self.iq)) + + iq = self.iq[xmin : xmax] + time = self.time[xmin : xmax] + + iq_fft = self.dofft(iq) + freq = self.calc_freq(time, self.sample_rate) + + self.plot_fft[0].set_data(freq, iq_fft) + self.sp_fft.axis([freq.min(), freq.max(), + iq_fft.min()-10, iq_fft.max()+10]) + + draw() + + def click(self, event): + forward_valid_keys = [" ", "down", "right"] + backward_valid_keys = ["up", "left"] + + if(find(event.key, forward_valid_keys)): + self.step_forward() + + elif(find(event.key, backward_valid_keys)): + self.step_backward() + + def button_left_click(self, event): + self.step_backward() + + def button_right_click(self, event): + self.step_forward() + + def step_forward(self): + self.get_data() + self.update_plots() + + def step_backward(self): + # Step back in file position + if(self.hfile.tell() >= 2*self.sizeof_data*self.block_length ): + self.hfile.seek(-2*self.sizeof_data*self.block_length, 1) + else: + self.hfile.seek(-self.hfile.tell(),1) + self.get_data() + self.update_plots() + + @staticmethod + def setup_options(): + usage="%prog: [options] input_filename" + description = "Takes a GNU Radio complex binary file and displays the I&Q data versus time as well as the frequency domain (FFT) plot. The y-axis values are plotted assuming volts as the amplitude of the I&Q streams and converted into dBm in the frequency domain (the 1/N power adjustment out of the FFT is performed internally). The script plots a certain block of data at a time, specified on the command line as -B or --block. This value defaults to 1000. The start position in the file can be set by specifying -s or --start and defaults to 0 (the start of the file). By default, the system assumes a sample rate of 1, so in time, each sample is plotted versus the sample number. To set a true time and frequency axis, set the sample rate (-R or --sample-rate) to the sample rate used when capturing the samples." + + parser = OptionParser(conflict_handler="resolve", usage=usage, description=description) + parser.add_option("-d", "--data-type", type="string", default="complex64", + help="Specify the data type (complex64, float32, (u)int32, (u)int16, (u)int8) [default=%default]") + parser.add_option("-B", "--block", type="int", default=1000, + help="Specify the block size [default=%default]") + parser.add_option("-s", "--start", type="int", default=0, + help="Specify where to start in the file [default=%default]") + parser.add_option("-R", "--sample-rate", type="float", default=1.0, + help="Set the sampler rate of the data [default=%default]") + return parser + +def find(item_in, list_search): + try: + return list_search.index(item_in) != None + except ValueError: + return False + +def main(): + parser = plot_fft_base.setup_options() + (options, args) = parser.parse_args () + if len(args) != 1: + parser.print_help() + raise SystemExit, 1 + filename = args[0] + + dc = plot_fft_base(options.data_type, filename, options) + +if __name__ == "__main__": + try: + main() + except KeyboardInterrupt: + pass + + + |