gprMax/tools/plot_Ascan.py

# Copyright (C) 2015-2023: The University of Edinburgh
#                 Authors: Craig Warren and Antonis Giannopoulos
#
# This file is part of gprMax.
#
# gprMax 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 of the License, or
# (at your option) any later version.
#
# gprMax 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 gprMax.  If not, see <http://www.gnu.org/licenses/>.

import argparse
import os
import sys

import h5py
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.gridspec as gridspec

from gprMax.exceptions import CmdInputError
from gprMax.receivers import Rx
from gprMax.utilities import fft_power


def mpl_plot(filename, outputs=Rx.defaultoutputs, fft=False):
    """Plots electric and magnetic fields and currents from all receiver points in the given output file. Each receiver point is plotted in a new figure window.

    Args:
        filename (string): Filename (including path) of output file.
        outputs (list): List of field/current components to plot.
        fft (boolean): Plot FFT switch.

    Returns:
        plt (object): matplotlib plot object.
    """

    # Open output file and read some attributes
    f = h5py.File(filename, 'r')
    nrx = f.attrs['nrx']
    dt = f.attrs['dt']
    iterations = f.attrs['Iterations']
    time = np.linspace(0, (iterations - 1) * dt, num=iterations)

    # Check there are any receivers
    if nrx == 0:
        raise CmdInputError('No receivers found in {}'.format(filename))

    # Check for single output component when doing a FFT
    if fft:
        if not len(outputs) == 1:
            raise CmdInputError('A single output must be specified when using the -fft option')

    # New plot for each receiver
    for rx in range(1, nrx + 1):
        path = '/rxs/rx' + str(rx) + '/'
        availableoutputs = list(f[path].keys())

        # If only a single output is required, create one subplot
        if len(outputs) == 1:

            # Check for polarity of output and if requested output is in file
            if outputs[0][-1] == '-':
                polarity = -1
                outputtext = '-' + outputs[0][0:-1]
                output = outputs[0][0:-1]
            else:
                polarity = 1
                outputtext = outputs[0]
                output = outputs[0]

            if output not in availableoutputs:
                raise CmdInputError('{} output requested to plot, but the available output for receiver 1 is {}'.format(output, ', '.join(availableoutputs)))

            outputdata = f[path + output][:] * polarity

            # Plotting if FFT required
            if fft:
                # FFT
                freqs, power = fft_power(outputdata, dt)
                freqmaxpower = np.where(np.isclose(power, 0))[0][0]

                # Set plotting range to -60dB from maximum power or 4 times
                # frequency at maximum power
                try:
                    pltrange = np.where(power[freqmaxpower:] < -60)[0][0] + freqmaxpower + 1
                except:
                    pltrange = freqmaxpower * 4

                pltrange = np.s_[0:pltrange]

                # Plot time history of output component
                fig, (ax1, ax2) = plt.subplots(nrows=1, ncols=2, num='rx' + str(rx), figsize=(20, 10), facecolor='w', edgecolor='w')
                line1 = ax1.plot(time, outputdata, 'r', lw=2, label=outputtext)
                ax1.set_xlabel('Time [s]')
                ax1.set_ylabel(outputtext + ' field strength [V/m]')
                ax1.set_xlim([0, np.amax(time)])
                ax1.grid(which='both', axis='both', linestyle='-.')

                # Plot frequency spectra
                markerline, stemlines, baseline = ax2.stem(freqs[pltrange], power[pltrange], '-.', use_line_collection=True)
                plt.setp(baseline, 'linewidth', 0)
                plt.setp(stemlines, 'color', 'r')
                plt.setp(markerline, 'markerfacecolor', 'r', 'markeredgecolor', 'r')
                line2 = ax2.plot(freqs[pltrange], power[pltrange], 'r', lw=2)
                ax2.set_xlabel('Frequency [Hz]')
                ax2.set_ylabel('Power [dB]')
                ax2.grid(which='both', axis='both', linestyle='-.')

                # Change colours and labels for magnetic field components or currents
                if 'H' in outputs[0]:
                    plt.setp(line1, color='g')
                    plt.setp(line2, color='g')
                    plt.setp(ax1, ylabel=outputtext + ' field strength [A/m]')
                    plt.setp(stemlines, 'color', 'g')
                    plt.setp(markerline, 'markerfacecolor', 'g', 'markeredgecolor', 'g')
                elif 'I' in outputs[0]:
                    plt.setp(line1, color='b')
                    plt.setp(line2, color='b')
                    plt.setp(ax1, ylabel=outputtext + ' current [A]')
                    plt.setp(stemlines, 'color', 'b')
                    plt.setp(markerline, 'markerfacecolor', 'b', 'markeredgecolor', 'b')

                plt.show()

            # Plotting if no FFT required
            else:
                fig, ax = plt.subplots(subplot_kw=dict(xlabel='Time [s]', ylabel=outputtext + ' field strength [V/m]'), num='rx' + str(rx), figsize=(20, 10), facecolor='w', edgecolor='w')
                line = ax.plot(time, outputdata, 'r', lw=2, label=outputtext)
                ax.set_xlim([0, np.amax(time)])
                # ax.set_ylim([-15, 20])
                ax.grid(which='both', axis='both', linestyle='-.')

                if 'H' in output:
                    plt.setp(line, color='g')
                    plt.setp(ax, ylabel=outputtext + ', field strength [A/m]')
                elif 'I' in output:
                    plt.setp(line, color='b')
                    plt.setp(ax, ylabel=outputtext + ', current [A]')

        # If multiple outputs required, create all nine subplots and populate only the specified ones
        else:
            fig, ax = plt.subplots(subplot_kw=dict(xlabel='Time [s]'), num='rx' + str(rx), figsize=(20, 10), facecolor='w', edgecolor='w')
            if len(outputs) == 9:
                gs = gridspec.GridSpec(3, 3, hspace=0.3, wspace=0.3)
            else:
                gs = gridspec.GridSpec(3, 2, hspace=0.3, wspace=0.3)

            for output in outputs:
                # Check for polarity of output and if requested output is in file
                if output[-1] == 'm':
                    polarity = -1
                    outputtext = '-' + output[0:-1]
                    output = output[0:-1]
                else:
                    polarity = 1
                    outputtext = output

                # Check if requested output is in file
                if output not in availableoutputs:
                    raise CmdInputError('Output(s) requested to plot: {}, but available output(s) for receiver {} in the file: {}'.format(', '.join(outputs), rx, ', '.join(availableoutputs)))

                outputdata = f[path + output][:] * polarity

                if output == 'Ex':
                    ax = plt.subplot(gs[0, 0])
                    ax.plot(time, outputdata, 'r', lw=2, label=outputtext)
                    ax.set_ylabel(outputtext + ', field strength [V/m]')
                # ax.set_ylim([-15, 20])
                elif output == 'Ey':
                    ax = plt.subplot(gs[1, 0])
                    ax.plot(time, outputdata, 'r', lw=2, label=outputtext)
                    ax.set_ylabel(outputtext + ', field strength [V/m]')
                # ax.set_ylim([-15, 20])
                elif output == 'Ez':
                    ax = plt.subplot(gs[2, 0])
                    ax.plot(time, outputdata, 'r', lw=2, label=outputtext)
                    ax.set_ylabel(outputtext + ', field strength [V/m]')
                # ax.set_ylim([-15, 20])
                elif output == 'Hx':
                    ax = plt.subplot(gs[0, 1])
                    ax.plot(time, outputdata, 'g', lw=2, label=outputtext)
                    ax.set_ylabel(outputtext + ', field strength [A/m]')
                # ax.set_ylim([-0.03, 0.03])
                elif output == 'Hy':
                    ax = plt.subplot(gs[1, 1])
                    ax.plot(time, outputdata, 'g', lw=2, label=outputtext)
                    ax.set_ylabel(outputtext + ', field strength [A/m]')
                # ax.set_ylim([-0.03, 0.03])
                elif output == 'Hz':
                    ax = plt.subplot(gs[2, 1])
                    ax.plot(time, outputdata, 'g', lw=2, label=outputtext)
                    ax.set_ylabel(outputtext + ', field strength [A/m]')
                # ax.set_ylim([-0.03, 0.03])
                elif output == 'Ix':
                    ax = plt.subplot(gs[0, 2])
                    ax.plot(time, outputdata, 'b', lw=2, label=outputtext)
                    ax.set_ylabel(outputtext + ', current [A]')
                elif output == 'Iy':
                    ax = plt.subplot(gs[1, 2])
                    ax.plot(time, outputdata, 'b', lw=2, label=outputtext)
                    ax.set_ylabel(outputtext + ', current [A]')
                elif output == 'Iz':
                    ax = plt.subplot(gs[2, 2])
                    ax.plot(time, outputdata, 'b', lw=2, label=outputtext)
                    ax.set_ylabel(outputtext + ', current [A]')
            for ax in fig.axes:
                ax.set_xlim([0, np.amax(time)])
                ax.grid(which='both', axis='both', linestyle='-.')

        # Save a PDF/PNG of the figure
        # fig.savefig(os.path.splitext(os.path.abspath(filename))[0] + '_rx' + str(rx) + '.pdf', dpi=None, format='pdf', bbox_inches='tight', pad_inches=0.1)
        # fig.savefig(os.path.splitext(os.path.abspath(filename))[0] + '_rx' + str(rx) + '.png', dpi=150, format='png', bbox_inches='tight', pad_inches=0.1)

    f.close()

    return plt


if __name__ == "__main__":

    # Parse command line arguments
    parser = argparse.ArgumentParser(description='Plots electric and magnetic fields and currents from all receiver points in the given output file. Each receiver point is plotted in a new figure window.', usage='cd gprMax; python -m tools.plot_Ascan outputfile')
    parser.add_argument('outputfile', help='name of output file including path')
    parser.add_argument('--outputs', help='outputs to be plotted', default=Rx.defaultoutputs, choices=['Ex', 'Ey', 'Ez', 'Hx', 'Hy', 'Hz', 'Ix', 'Iy', 'Iz', 'Ex-', 'Ey-', 'Ez-', 'Hx-', 'Hy-', 'Hz-', 'Ix-', 'Iy-', 'Iz-'], nargs='+')
    parser.add_argument('-fft', action='store_true', help='plot FFT (single output must be specified)', default=False)
    args = parser.parse_args()

    plthandle = mpl_plot(args.outputfile, args.outputs, fft=args.fft)
    plthandle.show()