hist_plot.py

#!/usr/bin/python

from math import ceil
import numpy as np
import matplotlib as mlp
import matplotlib.pyplot as plt


mlp.rcParams['mathtext.fontset'] = 'stix'
mlp.rcParams['font.family'] = 'STIXGeneral'
mlp.pyplot.title(r'ABC123 vs $\mathrm{ABC123}^{123}$')

mlp.rcParams['axes.labelsize']  = 15
mlp.rcParams['axes.titlesize']  = 20
mlp.rcParams['xtick.labelsize'] = 15
mlp.rcParams['ytick.labelsize'] = 15


def reject_outliers(data, m=2):
    return data[abs(data - np.mean(data)) < m * np.std(data)]

def plotDistanceHistogram (distances_real, distances_false, name):
    distances_real = reject_outliers (distances_real, 3)
    distances_false = reject_outliers (distances_false, 3)

    weights_real = (np.ones_like (distances_real)) / len (distances_real)
    n, bins_n, patches_n = plt.hist (distances_real, 50, weights = weights_real, histtype = 'bar')

    weights_false = (np.ones_like (distances_false)) / len (distances_false)
    m, bins_m, patches_m = plt.hist (distances_false, 50, weights = weights_false, histtype = 'bar')

    plt.clf ()

    x = [bins_n[0]] + [0.5 * (bins_n[i] + bins_n[i + 1]) for i in xrange (len(bins_n) - 1)] + [bins_n[-1]]
    y = [0.0] + [patch.get_height () for patch in patches_n] + [0.0]
    plt.plot (x, y, color = 'green', alpha = 0.75, label = 'correspondencias reales', marker = 'o')
    plt.fill (x, y, color = 'green', alpha = 0.75)

    x = [bins_m[0]] + [0.5 * (bins_m[i] + bins_m[i + 1]) for i in xrange (len(bins_m) - 1)] + [bins_m[-1]]
    y = [0.0] + [patch.get_height () for patch in patches_m] + [0.0]
    plt.plot (x, y, color = 'red', alpha = 0.75, label = 'correspondencias falsas', marker = 'o')
    plt.fill (x, y, color = 'red', alpha = 0.75)

    plt.legend (bbox_to_anchor = (0., 1., 1., .12), loc = 'upper center', ncol = 2, mode = 'expand', fontsize = 15)
    plt.grid (True)

    plt.savefig ('histograma-distancias-' + name + '.png', bbox_inches = 'tight')


def main ():
    mu, sigma = 0.25, 0.05
    x = mu + sigma * np.random.randn (10000)
    y = x + 0.2

    plotDistanceHistogram (x, y, 'prueba')


if __name__ == "__main__":
    main ()