adze.py

 # Copyright (C) 2018-2019 Greenweaves Software Limited
 #
 # This 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.

 # This software 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 this software.  If not, see <http://www.gnu.org/licenses/>
 #
 # Companion to galaxy.exe - cut up logfiles


import re,matplotlib.pyplot as plt

# Extract energies and plot them

def plot_files(
    file_names=[],
    plot_file='energies.png',
    colours=['r','g','b','m','c','y']):
    for i in range(len(file_names)):
        energies=[]
        t=[]
        j=0
        dt=0.001
        m=0
        n=0
        for line in open(file_names[i]):
            match=re.match(r'.*dt=([-+e\.0-9]+)',line.strip())
            if match:
                dt=float(match.group(1))
            match=re.match(r'.* Number of iterations=([-+e\.0-9]+)',line.strip())
            if match:
                m=int(match.group(1))
            match=re.match(r'.* Number of bodies=([-+e\.0-9]+)',line.strip())
            if match:
                n=int(match.group(1))            
            match=re.match(r'.*Energy +([-+e\.0-9]+)',line.strip())
            if match:
                energies.append(float(match.group(1)))
                j+=1
                t.append(j*dt)
        plt.plot(t,energies,c=colours[i],label='dt={0},m={1},n={2}'.format(dt,m,n))
        plt.plot([t[0],t[-1]],[energies[0],energies[0]],c=colours[i],linestyle=':')
    plt.title('Total Energy')
    plt.legend(loc='best')
    plt.savefig(plot_file)
    
if __name__=='__main__':
    import argparse
    parser = argparse.ArgumentParser(description='Extract energy from logfiles and plot it')
    parser.add_argument('--logs', '-l',metavar='N', type=str, nargs='+',help='Logfiles to be plotted')
    parser.add_argument('--output', '-o',metavar='N', type=str, nargs='+',help='Name of plot file')   
    args = parser.parse_args() 
    plot_files(file_names=args.logs,plot_file=args.output)
    plt.show()