gr_plot_iq

#!/usr/bin/env python
#
# Copyright 2007,2008,2011 Free Software Foundation, Inc.
#
# This file is part of GNU Radio
#
# SPDX-License-Identifier: GPL-3.0-or-later
#
#

import numpy

try:
    from pylab import (
        Button,
        connect,
        draw,
        figtext,
        figure,
        get_current_fig_manager,
        plot,
        rcParams,
        show,
    )
except ImportError:
    print(
        "Please install Python Matplotlib (http://matplotlib.sourceforge.net/) and \
           Python TkInter https://wiki.python.org/moin/TkInter to run this script"
    )
    raise SystemExit(1)

from argparse import ArgumentParser


class draw_iq:
    def __init__(self, filename, options):
        self.hfile = open(filename, "r")
        self.block_length = options.block
        self.start = options.start
        self.sample_rate = options.sample_rate

        self.datatype = numpy.complex64
        # number of bytes per sample in file
        self.sizeof_data = self.datatype().nbytes

        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, 9), 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(
            0.40,
            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("key_press_event", self.click)
        show()

    def get_data(self):
        self.text_file_pos.set_text(
            "File Position: %d" % (self.hfile.tell() // self.sizeof_data)
        )
        try:
            self.iq = numpy.fromfile(
                self.hfile, dtype=self.datatype, count=self.block_length
            )
        except MemoryError:
            print("End of File")
        else:
            self.reals = numpy.array([r.real for r in self.iq])
            self.imags = numpy.array([i.imag for i in self.iq])
            self.time = numpy.array(
                [i * (1 / self.sample_rate) for i in range(len(self.reals))]
            )

    def make_plots(self):
        # if specified on the command-line, set file pointer
        self.hfile.seek(self.sizeof_data * self.start, 1)

        self.get_data()

        # Subplot for real and imaginary parts of signal
        self.sp_iq = self.fig.add_subplot(
            2, 1, 1, position=[0.075, 0.14, 0.85, 0.67])
        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"
        )
        self.plot_iq = plot(self.time, self.reals, "bo-",
                            self.time, self.imags, "ro-")
        self.sp_iq.set_ylim(
            [
                1.5 * min([self.reals.min(), self.imags.min()]),
                1.5 * max([self.reals.max(), self.imags.max()]),
            ]
        )
        self.sp_iq.set_xlim(self.time.min(), self.time.max())
        draw()

    def update_plots(self):
        self.plot_iq[0].set_data([self.time, self.reals])
        self.plot_iq[1].set_data([self.time, self.imags])
        self.sp_iq.set_ylim(
            [
                1.5 * min([self.reals.min(), self.imags.min()]),
                1.5 * max([self.reals.max(), self.imags.max()]),
            ]
        )
        self.sp_iq.set_xlim(self.time.min(), self.time.max())
        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) is not None
    except ValueError:
        return False


def main():
    description = "Takes a GNU Radio complex binary file and displays the I&Q data versus time. You can set the block size to specify how many points to read in at a time and the start position in 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 axis, set the sample rate (-R or --sample-rate) to the sample rate used when capturing the samples."

    parser = ArgumentParser(conflict_handler="resolve",
                            description=description)
    parser.add_argument(
        "-B",
        "--block",
        type=int,
        default=1000,
        help="Specify the block size [default=%(default)r]",
    )
    parser.add_argument(
        "-s",
        "--start",
        type=int,
        default=0,
        help="Specify where to start in the file [default=%(default)r]",
    )
    parser.add_argument(
        "-R",
        "--sample-rate",
        type=float,
        default=1.0,
        help="Set the sampler rate of the data [default=%(default)r]",
    )
    parser.add_argument("file", metavar="FILE",
                        help="Input file with complex samples")

    args = parser.parse_args()

    dc = draw_iq(args.file, args)


if __name__ == "__main__":
    try:
        main()
    except KeyboardInterrupt:
        pass