Use matplotlib to plot in a column from several ascii data files

one_column_subplot.py

#!/usr/bin/env python

# Requires numpy and matplotlib

# This file is in public domain

def usage():
    import sys

    print >>sys.stderr, sys.argv[0] + " [options] file1 [file2 file3 ...]"
    print >>sys.stderr, """
Options:
    -x OR --xlabel      Spedify the x label
    --xmin              The x minimum limit
    --xmax              The x maximum limit
    --ymin              The y minimum limit
    --ymax              The y maximum limit
    --face-color        The filling color list separated by ':'. See
                            http://matplotlib.sourceforge.net/api/colors_api.html#module-matplotlib.colors
                        for the color list.
    -y OR --ylabel      Specify a y label. If you have multiple plots, each -y or --ylabel will specify one.
    --no-y-ticks        Don't display any ticks on y axis.
    """

def main():
    import sys
    import numpy
    import getopt
    import matplotlib.pyplot as plt

    if len(sys.argv) <= 1:
        usage()
        sys.exit(2)

    try:
        opts, args = getopt.getopt(sys.argv[1:], 'x:y:',
                ['xlabel=', 'xmin=', 'xmax=', 'ymin=', 'ymax=', 'face-color=', 'ylabel=', 'no-y-ticks'])
    except getopt.GetoptError as err:
        print >>sys.stderr, str(err)
        print >>sys.stderr, ''
        usage()
        sys.exit(1)

    xmin = None
    xmax = None
    ymin = None
    ymax = None
    no_y_ticks = False
    xlabel = ''  # default xlabel is empty
    face_color_list = []
    ylabel_list = []
    for o, a in opts:
        if o in ("-x", "--xlabel"):
            xlabel = a
        elif o in ("-y", "--ylabel"):
            ylabel_list.append(a)
        elif o == "--xmin":
            xmin = float(a)
        elif o == "--xmax":
            xmax = float(a)
        elif o == "--ymin":
            ymin = float(a)
        elif o == "--ymax":
            ymax = float(a)
        elif o == "--face-color":
            face_color_list = a.split(':')
        elif o == "--no-y-ticks":
            no_y_ticks = True
        else:
            assert False, "unhandled option"

    data = []
    for filename in args:
        data.append(numpy.loadtxt(filename, usecols = (0, 1)))

    # the number of plots
    plot_count = len(data)
    if plot_count <= 0:
        usage()
        sys.exit(3)

    # the color is blue by default
    if len(face_color_list) > plot_count:
        del face_color_list[plot_count:]
    elif len(face_color_list) < plot_count:
        face_color_list.extend( [ 'b' for i in range(len(face_color_list), plot_count + 1) ] )

    # ylabel is empty by default
    if len(ylabel_list) > plot_count:
        del ylabel_list[plot_count:]
    elif len(ylabel_list) < plot_count:
        ylabel_list.extend( [ '' for i in range(len(ylabel_list), plot_count + 1) ] )

    f, axes = plt.subplots(plot_count, sharex = True, sharey = True)
    f.subplots_adjust(hspace = 0)
    for one_data, ax, facecolor, ylabel in zip(data, axes, face_color_list, ylabel_list):
        ax.fill_between(one_data[:, 0], one_data[:, 1], facecolor = facecolor)
        plt.xlim(xmin, xmax)
        plt.ylim(ymin, ymax)
        if no_y_ticks:
            plt.yticks([])
        ax.set_ylabel(ylabel)
        

    plt.xlabel(xlabel)

    plt.show()

if __name__ == '__main__':
    main()