summary.py

"""
A stand-alone script to print summary statistics about a data file.
Runs without arguments - GUI dialogs are used to select the
chain and info files.
"""

from prettytable import PrettyTable as pt
import data_loader

from super_gui import open_file_gui

from plot_options import default
import statslib.point as stats
import statslib.one_dim as one_dim


def _summary(name, param, posterior, chi_sq):
    """
    Find summary statistics for a single parameter.
    
    :param name: Name of parameter
    :type name: string
    :param param: Data column of parameter
    :type param:
    :param posterior:
    :type posterior:
    :param chi_sq:
    :type chi_sq:
    
    :returns: List of summary statistics for a particular parameter
    :rtype: list
    """

    # Best-fit point
    bestfit = stats.best_fit(chi_sq, param)

    # Posterior mean
    post_mean = stats.posterior_mean(posterior, param)

    # Credible regions
    pdf_data = one_dim.posterior_pdf(param,
                                     posterior,
                                     nbins=default("nbins"),
                                     bin_limits=default("bin_limits")
                                     )

    lower_credible_region = one_dim.credible_region(pdf_data.pdf,
                                                    pdf_data.bin_centers,
                                                    alpha=default("alpha")[1],
                                                    region="lower")
    upper_credible_region = one_dim.credible_region(pdf_data.pdf,
                                                    pdf_data.bin_centers,
                                                    alpha=default("alpha")[1],
                                                    region="upper")

    summary = [name,
               bestfit,
               post_mean,
               lower_credible_region,
               upper_credible_region
               ]

    return summary


def _summary_table(labels, data, names=None, datafile=None, infofile=None):
    """
    Summarize multiple parameters in a table.
    
    :returns: Table of summary statistics for particular parameters
    :rtype: string
    """

    # Summarize all parameters by default
    if names is None:
        names = labels.values()

    # Make a string describing credible interval
    beta_percent = 100. * (1. - default("alpha")[1])
    credible_name = "%.2g%% credible region" % beta_percent

    # Headings for a table
    headings = ["Name",
                "best-fit",
                "posterior mean",
                credible_name,
                ""
                ]
    param_table = pt(headings)
    param_table.align = "l"
    param_table.float_format = "4.2"

    # Make summary data and add it to table
    posterior = data[0]
    chi_sq = data[1]

    for key, name in labels.iteritems():
        if name in names:
            param = data[key]
            param_table.add_row(_summary(name, param, posterior, chi_sq))

    # Best-fit information and information about chain
    min_chi_sq = data[1].min()
    p_value = stats.p_value(data[1], default("dof"))
    bestfit_table = pt(header=False)
    bestfit_table.align = "l"
    bestfit_table.float_format = "4.2"
    bestfit_table.add_row(["File", datafile])
    bestfit_table.add_row(["Info-file", infofile])
    bestfit_table.add_row(["Minimum chi-squared", min_chi_sq])
    bestfit_table.add_row(["p-value", p_value])

    return bestfit_table.get_string() + "\n\n" + param_table.get_string()


def main():
    # Select chain and info file with a GUI.
    datafile = open_file_gui()
    infofile = open_file_gui()

    # Load and label data
    labels, data = data_loader.load(infofile, datafile)

    summary_table = _summary_table(labels, data, datafile=datafile, infofile=infofile)
    return summary_table


if __name__ == "__main__":
    print main()