Source code for jmetal.lab.visualization.posterior

import logging

import numpy as np
import pandas as pd
from matplotlib import pyplot as plt

logger = logging.getLogger(__name__)


[docs] def plot_posterior( sample, higher_is_better: bool = False, min_points_per_hexbin: int = 2, alg_names: list = None, filename: str = "posterior.eps", ): """ Plots the sample from posterior distribution of a Bayesian statistical test. Parameters: ----------- data: An (n x 3) array or DataFrame contaning the probabilities. alg_names: array of strings. Default np.array(['Alg1', 'Alg2']) Names of the algorithms under evaluation Return: ------- Figure """ # Initial Checking if type(sample) == pd.DataFrame: sample = sample.values if sample.ndim == 2: nrow, ncol = sample.shape if ncol != 3: raise ValueError("Initialization ERROR. Incorrect number of dimensions in axis 1.") else: raise ValueError("Initialization ERROR. Incorrect number of dimensions for sample") def transform(p): lambda1, lambda2, lambda3 = p.T x = 0.1 * lambda1 + 0.5 * lambda2 + 0.9 * lambda3 y = (0.2 * lambda1 + 1.4 * lambda2 + 0.2 * lambda3) / np.sqrt(3) return np.vstack((x, y)).T # Initialize figure fig = plt.figure(figsize=(5, 5), facecolor="white") ax = fig.add_axes([0, 0, 1, 1]) ax.set_xlim(0, 1) ax.set_ylim(0, 1) ax.set_axis_off() # plot text if not higher_is_better: if not alg_names: ax.text(x=0.5, y=1.4 / np.sqrt(3) + 0.005, s="P(rope)", ha="center", va="bottom") ax.text(x=0.15, y=0.175 / np.sqrt(3) - 0.005, s="P(alg1<alg2)", ha="right", va="top") ax.text(x=0.85, y=0.175 / np.sqrt(3) - 0.005, s="P(alg1>alg2)", ha="left", va="top") else: ax.text(x=0.5, y=1.4 / np.sqrt(3) + 0.005, s="P(rope)", ha="center", va="bottom") ax.text(x=0.15, y=0.175 / np.sqrt(3) - 0.005, s="P(" + alg_names[0] + ")", ha="right", va="top") ax.text(x=0.85, y=0.175 / np.sqrt(3) - 0.005, s="P(" + alg_names[1] + ")", ha="left", va="top") else: if not alg_names: ax.text(x=0.5, y=1.4 / np.sqrt(3) + 0.005, s="P(rope)", ha="center", va="bottom") ax.text(x=0.15, y=0.175 / np.sqrt(3) - 0.005, s="P(alg2<alg1)", ha="right", va="top") ax.text(x=0.85, y=0.175 / np.sqrt(3) - 0.005, s="P(alg2>alg1)", ha="left", va="top") else: ax.text(x=0.5, y=1.4 / np.sqrt(3) + 0.005, s="P(rope)", ha="center", va="bottom") ax.text(x=0.15, y=0.175 / np.sqrt(3) - 0.005, s="P(" + alg_names[1] + ")", ha="right", va="top") ax.text(x=0.85, y=0.175 / np.sqrt(3) - 0.005, s="P(" + alg_names[0] + ")", ha="left", va="top") # Conversion between barycentric and Cartesian coordinates sample2d = np.zeros((sample.shape[0], 2)) for p in range(sample.shape[0]): sample2d[p, :] = transform(sample[p, :]) # Plot projected points ax.hexbin(sample2d[:, 0], sample2d[:, 1], mincnt=min_points_per_hexbin, cmap=plt.cm.plasma) # Plot triangle ax.plot([0.095, 0.505], [0.2 / np.sqrt(3), 1.4 / np.sqrt(3)], linewidth=3.0, color="white") ax.plot([0.505, 0.905], [1.4 / np.sqrt(3), 0.2 / np.sqrt(3)], linewidth=3.0, color="white") ax.plot([0.09, 0.905], [0.2 / np.sqrt(3), 0.2 / np.sqrt(3)], linewidth=3.0, color="white") ax.plot([0.1, 0.5], [0.2 / np.sqrt(3), 1.4 / np.sqrt(3)], linewidth=3.0, color="gray") ax.plot([0.5, 0.9], [1.4 / np.sqrt(3), 0.2 / np.sqrt(3)], linewidth=3.0, color="gray") ax.plot([0.1, 0.9], [0.2 / np.sqrt(3), 0.2 / np.sqrt(3)], linewidth=3.0, color="gray") # plot division lines ax.plot([0.5, 0.5], [0.2 / np.sqrt(3), 0.6 / np.sqrt(3)], linewidth=3.0, color="gray") ax.plot([0.3, 0.5], [0.8 / np.sqrt(3), 0.6 / np.sqrt(3)], linewidth=3.0, color="gray") ax.plot([0.5, 0.7], [0.6 / np.sqrt(3), 0.8 / np.sqrt(3)], linewidth=3.0, color="gray") if filename: plt.savefig(filename, bbox_inches="tight") logger.info(f"Figure {filename} saved to file") plt.show()