1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
|
#!/usr/bin/env python
#
# Copyright 2007,2008 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 gr_plot_fft:
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))
self.iq = scipy.fromfile(self.hfile, dtype=self.datatype, count=self.block_length)
#print "Read in %d items" % len(self.iq)
if(len(self.iq) == 0):
print "End of File"
else:
self.iq_fft = self.dofft(self.iq)
tstep = 1.0 / self.sample_rate
self.time = [tstep*(self.position + 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 = 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 / (max(time) - min(time))
Fn = 0.5 * sample_rate
freq = [-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(min(self.time), max(self.time))
self.sp_iq.set_ylim([1.5*min([min(reals), min(imags)]),
1.5*max([max(reals), max(imags)])])
def draw_fft(self):
self.plot_fft[0].set_data([self.freq, self.iq_fft])
self.sp_fft.set_xlim(min(self.freq), max(self.freq))
self.sp_fft.set_ylim([min(self.iq_fft)-10, max(self.iq_fft)+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.all() != curxlim.all()):
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))
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([min(freq), max(freq),
min(iq_fft)-10, max(iq_fft)+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()
def find(item_in, list_search):
try:
return list_search.index(item_in) != None
except ValueError:
return False
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 main():
parser = setup_options()
(options, args) = parser.parse_args ()
if len(args) != 1:
parser.print_help()
raise SystemExit, 1
filename = args[0]
dc = gr_plot_fft(options.data_type, filename, options)
if __name__ == "__main__":
try:
main()
except KeyboardInterrupt:
pass
|
