test_generate_rej_given_data.py

import numpy
from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
plt.ion()

from sklearn.decomposition import PCA

from cwc.data_wrappers import toy_examples
from cwc.data_wrappers import reject


def test_rej_data():
    samples = [500, 500]
    x, y = toy_examples.generate_gaussians(means=[[3,3,3],[5,5,5]],
                                  covs=[[[2,1,0],[1,1,0],[0,0,1]],
                                        [[1,0,0],[0,1,1],[0,1,2]]],
                                  samples=samples)
    fig = plt.figure('data')
    ax = fig.add_subplot(111, projection='3d')

    for k, c in [(0, 'r'), (1, 'b')]:
        index = (y == k)
        ax.scatter(x[index,0], x[index,1], x[index,2], c=c)

    pca = PCA(n_components=2, whiten=True)
    pca.fit(x)

    fig = plt.figure('pca')
    plt.clf()
    x_transform = pca.transform(x)
    for k, c in [(0, 'r'), (1, 'b')]:
        index = (y == k)
        plt.scatter(x_transform[index,0], x_transform[index,1], c=c)


    x_transform_means = x_transform.mean(axis=0)
    x_transform_std = x_transform.std(axis=0)

    radius=1
    r = reject.hypersphere_distribution(numpy.sum(samples),pca.n_components,
                                        radius=radius)
    # TODO compute the value of r before creating the hypersphere
    r *= numpy.sqrt(1.1/(numpy.mean(r**2)))

    plt.scatter(r[:,0], r[:,1], c='y')

    r_transform = pca.inverse_transform(r)

    ax.scatter(r_transform[:,0], r_transform[:,1], r_transform[:,2], c='y')

def test_rej_data_given_x():

    # Options for data generation
    samples = [700,         # Class 1
               500,         # Class 2
               400]         # Class 3
    means = [[3,3,3],       # Class 1
             [5,5,5],       # Class 2
             [3,5,5]]       # Class 3
    covs = [[[2,1,0],       # Class 1
             [1,2,0],
             [0,0,1]],
            [
             [1,0,0],       # Class 2
             [0,1,0],
             [0,0,1]],
            [
             [1,0,0],       # Class 3
             [0,1,1],
             [0,1,2]]]
    # Options for reject data generation
    proportion = 0.9
    hshape_cov = 0
    hshape_prop_in = 0.99
    hshape_multiplier = 1.5
    pca = True
    pca_components = 0
    pca_variance = 0.9

    # Options for plotting
    colors = ['r', 'b', 'g', 'y']    # One color per class + reject


    x, y = toy_examples.generate_gaussians(means=means, covs=covs,
                                           samples=samples)

    for method in ['uniform_hcube', 'uniform_hsphere']: # 'uniform_hcube', 'uniform_hsphere'
        fig = plt.figure(method)
        fig.clf()
        ax = fig.add_subplot(111, projection='3d')
        for k, c in enumerate(colors[:-1]):
            index = (y == k)
            ax.scatter(x[index,0], x[index,1], x[index,2], c=c)

        r = reject.create_reject_data(x, proportion=proportion,
                                      method=method, pca=pca,
                                      pca_variance=pca_variance,
                                      pca_components=pca_components,
                                      hshape_cov=hshape_cov,
                                      hshape_prop_in=hshape_prop_in,
                                      hshape_multiplier=hshape_multiplier)
        ax.scatter(r[:,0], r[:,1], r[:,2], c=colors[-1])

if __name__ == '__main__':
    test_rej_data_given_x()