Overlay two pickled figure objects

merge.py

"""
Merge two pickled plots
=======================

This is rather crude. The pickled plots should have identical sizes, axes etc.

"""

from pickle import load
from matplotlib.pyplot import figure
from argparse import ArgumentParser as arg_parser


def pickles_to_plot(pickle_names, combined_name="combined.pdf", alpha=0.3):
    """
    Combine pickled figures into a single figure.

    :param pickle_names: Name of pickled figures
    :type pickle_names: list of str
    :param combined_name: Name of resulting figure saved to disk
    :type combined_name: str
    :param alpha: Transparency of overlaid figures
    :type alpha: float
    """

    fig_handles = [load(open(f, 'rb')) for f in pickle_names]
    ax_handles = [f.gca() for f in fig_handles]
    figsize = fig_handles[0].get_size_inches()
    fig = figure(figsize=figsize)

    for a in ax_handles:
        a.patch.set_alpha(alpha)
        fig._axstack.add(fig._make_key(a), a)

    fig.tight_layout()
    fig.savefig(combined_name)

if __name__ == "__main__":

    parser = arg_parser(description="Merge pickled plots into a single figure.")

    parser.add_argument('pickle_names', nargs='+', type=str, help="Pickled figures")
    parser.add_argument('-n', '--combined_name', type=str, required=False, default='combined.pdf', help="Name of combined figure to save to disk")
    parser.add_argument('-a', '--alpha', type=float, required=False, default=0.3, help="Transparency of overlaid figures")

    args = parser.parse_args()
    pickles_to_plot(args.pickle_names, args.combined_name, args.alpha)