content: #!/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
  
  
  
  