def test_plot_decision_function(self):
"""Test plot of multiclass classifier decision function."""
# generate synthetic data
ds = CDLRandom(n_classes=3, n_features=2, n_redundant=0,
n_clusters_per_class=1, class_sep=1,
random_state=0).load()
multiclass = CClassifierMulticlassOVA(
classifier=CClassifierSVM,
class_weight='balanced',
preprocess='min-max')
# Training and classification
multiclass.fit(ds.X, ds.Y)
y_pred, score_pred = multiclass.predict(
ds.X, return_decision_function=True)
def plot_hyperplane(img, clf, min_v, max_v, linestyle, label):
"""Plot the hyperplane associated to the OVA clf."""
xx = CArray.linspace(
min_v - 5, max_v + 5) # make sure the line is long enough
# get the separating hyperplane
yy = -(clf.w[0] * xx + clf.b) / clf.w[1]
img.sp.plot(xx, yy, linestyle, label=label)
fig = CFigure(height=7, width=8)
fig.sp.title('{:} ({:})'.format(multiclass.__class__.__name__,
multiclass.classifier.__name__))
x_bounds, y_bounds = ds.get_bounds()
styles = ['go-', 'yp--', 'rs-.', 'bD--', 'c-.', 'm-', 'y-.']
for c_idx, c in enumerate(ds.classes):
# Plot boundary and predicted label for each OVA classifier
plot_hyperplane(fig, multiclass._binary_classifiers[c_idx],
x_bounds[0], x_bounds[1], styles[c_idx],
'Boundary\nfor class {:}'.format(c))
fig.sp.scatter(ds.X[ds.Y == c, 0],
ds.X[ds.Y == c, 1],
s=40, c=styles[c_idx][0])
fig.sp.scatter(ds.X[y_pred == c, 0], ds.X[y_pred == c, 1], s=160,
edgecolors=styles[c_idx][0],
facecolors='none', linewidths=2)
# Plotting multiclass decision function
fig.sp.plot_decision_regions(multiclass, n_grid_points=100,
grid_limits=ds.get_bounds(offset=5))
fig.sp.xlim(x_bounds[0] - .5 * x_bounds[1],
x_bounds[1] + .5 * x_bounds[1])
fig.sp.ylim(y_bounds[0] - .5 * y_bounds[1],
y_bounds[1] + .5 * y_bounds[1])
fig.sp.legend(loc=4) # lower, right
fig.show()
def test_plot(self):
ds = CDLRandom(n_samples=100,
n_features=2,
n_redundant=0,
random_state=100).load()
self.logger.info("Train Sec SVM")
sec_svm = CClassifierSecSVM(C=1, eta=0.1, eps=1e-3, lb=-0.1, ub=0.5)
sec_svm.verbose = 2
sec_svm.fit(ds.X, ds.Y)
self.logger.info("Train SVM")
svm = CClassifierSVM(C=1)
svm.fit(ds.X, ds.Y)
self._compute_alignment(ds, sec_svm, svm)
fig = CFigure(height=5, width=8)
fig.subplot(1, 2, 1)
# Plot dataset points
fig.sp.plot_ds(ds)
# Plot objective function
fig.sp.plot_fun(svm.predict,
multipoint=True,
plot_background=True,
plot_levels=False,
n_grid_points=100,
grid_limits=ds.get_bounds())
fig.sp.title("SVM")
fig.subplot(1, 2, 2)
# Plot dataset points
fig.sp.plot_ds(ds)
# Plot objective function
fig.sp.plot_fun(sec_svm.predict,
multipoint=True,
plot_background=True,
plot_levels=False,
n_grid_points=100,
grid_limits=ds.get_bounds())
fig.sp.title("Sec-SVM")
fig.show()
def test_draw(self):
""" Compare the classifiers graphically"""
self.logger.info("Testing classifiers graphically")
# generate 2D synthetic data
dataset = CDLRandom(n_features=2,
n_redundant=1,
n_informative=1,
n_clusters_per_class=1).load()
dataset.X = CNormalizerMinMax().fit_transform(dataset.X)
self.sgds[0].fit(dataset.X, dataset.Y)
svm = CClassifierSVM()
svm.fit(dataset.X, dataset.Y)
fig = CFigure(width=10, markersize=8)
fig.subplot(2, 1, 1)
# Plot dataset points
fig.sp.plot_ds(dataset)
# Plot objective function
fig.sp.plot_fun(svm.decision_function,
grid_limits=dataset.get_bounds(),
y=1)
fig.sp.title('SVM')
fig.subplot(2, 1, 2)
# Plot dataset points
fig.sp.plot_ds(dataset)
# Plot objective function
fig.sp.plot_fun(self.sgds[0].decision_function,
grid_limits=dataset.get_bounds(),
y=1)
fig.sp.title('SGD Classifier')
fig.savefig(
fm.join(fm.abspath(__file__), 'figs',
'test_c_classifier_sgd1.pdf'))
class TestCAttackEvasionPGDLSMNIST(CAttackEvasionTestCases):
"""Unittests for CAttackEvasionPGDLS on MULTICLASS dataset."""
def setUp(self):
import numpy as np
np.random.seed(12345678)
# generate synthetic data
self.ds = CDLRandom(n_classes=3,
n_features=2,
n_redundant=0,
n_clusters_per_class=1,
class_sep=1,
random_state=0).load()
# Add a new class modifying one of the existing clusters
self.ds.Y[(self.ds.X[:, 0] > 0).logical_and(
self.ds.X[:, 1] > 1).ravel()] = self.ds.num_classes
# self.kernel = None
self.kernel = CKernelRBF(gamma=10)
# Data normalization
self.normalizer = CNormalizerMinMax()
self.ds.X = self.normalizer.fit_transform(self.ds.X)
self.multiclass = CClassifierMulticlassOVA(classifier=CClassifierSVM,
class_weight='balanced',
preprocess=None,
kernel=self.kernel)
self.multiclass.verbose = 0
# Training and classification
self.multiclass.fit(self.ds.X, self.ds.Y)
self.y_pred, self.score_pred = self.multiclass.predict(
self.ds.X, return_decision_function=True)
def test_indiscriminate(self):
"""Test indiscriminate evasion."""
self.y_target = None
self.logger.info("Test indiscriminate evasion ")
expected_x = CArray([0.1783, 0.6249])
self._test_evasion_multiclass(expected_x)
def test_targeted(self):
"""Test targeted evasion."""
self.y_target = 2
self.logger.info("Test target evasion "
"(with target class {:}) ".format(self.y_target))
expected_x = CArray([0.9347, 0.3976])
self._test_evasion_multiclass(expected_x)
def _test_evasion_multiclass(self, expected_x):
# EVASION
self.multiclass.verbose = 2
if self.normalizer is not None:
lb = self.normalizer.feature_range[0]
ub = self.normalizer.feature_range[1]
else:
lb = None
ub = None
dmax = 2
self.solver_params = {'eta': 1e-1, 'eta_min': 1.0}
eva = CAttackEvasionPGDLS(classifier=self.multiclass,
surrogate_classifier=self.multiclass,
surrogate_data=self.ds,
distance='l2',
dmax=dmax,
lb=lb,
ub=ub,
solver_params=self.solver_params,
y_target=self.y_target)
eva.verbose = 0 # 2
# Points from class 2 region
# p_idx = 0
# Points from class 1 region
# p_idx = 68
# Points from class 3 region
p_idx = 1 # Wrong classified point
# p_idx = 53 # Evasion goes up usually
# Points from class 0 region
# p_idx = 49 # Wrong classified point
# p_idx = 27 # Correctly classified point
x0 = self.ds.X[p_idx, :]
y0 = self.ds.Y[p_idx].item()
x_seq = CArray.empty((0, x0.shape[1]))
scores = CArray([])
f_seq = CArray([])
x = x0
for d_idx, d in enumerate(range(0, dmax + 1)):
self.logger.info("Evasion at dmax: " + str(d))
eva.dmax = d
x, f_opt = eva._run(x0=x0, y0=y0, x_init=x)
y_pred, score = self.multiclass.predict(
x, return_decision_function=True)
f_seq = f_seq.append(f_opt)
# not considering all iterations, just values at dmax
# for all iterations, you should bring eva.x_seq and eva.f_seq
x_seq = x_seq.append(x, axis=0)
s = score[:, y0 if self.y_target is None else self.y_target]
scores = scores.append(s)
self.logger.info("Predicted label after evasion: " + str(y_pred))
self.logger.info("Score after evasion: {:}".format(s))
self.logger.info("Objective function after evasion: {:}".format(f_opt))
# Compare optimal point with expected
self.assert_array_almost_equal(eva.x_opt.todense().ravel(),
expected_x,
decimal=4)
self._make_plots(x_seq, dmax, eva, x0, scores, f_seq)
def _make_plots(self, x_seq, dmax, eva, x0, scores, f_seq):
if self.make_figures is False:
self.logger.debug("Skipping figures...")
return
fig = CFigure(height=9, width=10, markersize=6, fontsize=12)
# Get plot bounds, taking into account ds and evaded point path
bounds_x, bounds_y = self.ds.get_bounds()
min_x, max_x = bounds_x
min_y, max_y = bounds_y
min_x = min(min_x, x_seq[:, 0].min())
max_x = max(max_x, x_seq[:, 0].max())
min_y = min(min_y, x_seq[:, 1].min())
max_y = max(max_y, x_seq[:, 1].max())
ds_bounds = [(min_x, max_x), (min_y, max_y)]
# Plotting multiclass decision regions
fig.subplot(2, 2, 1)
fig = self._plot_decision_function(fig, plot_background=True)
fig.sp.plot_path(x_seq,
path_style='-',
start_style='o',
start_facecolor='w',
start_edgewidth=2,
final_style='o',
final_facecolor='k',
final_edgewidth=2)
# plot distance constraint
fig.sp.plot_fun(func=self._rescaled_distance,
multipoint=True,
plot_background=False,
n_grid_points=20,
levels_color='k',
grid_limits=ds_bounds,
levels=[0],
colorbar=False,
levels_linewidth=2.0,
levels_style=':',
alpha_levels=.4,
c=x0,
r=dmax)
fig.sp.grid(linestyle='--', alpha=.5, zorder=0)
# Plotting multiclass evasion objective function
fig.subplot(2, 2, 2)
fig = self._plot_decision_function(fig)
fig.sp.plot_fgrads(eva._objective_function_gradient,
grid_limits=ds_bounds,
n_grid_points=20,
color='k',
alpha=.5)
fig.sp.plot_path(x_seq,
path_style='-',
start_style='o',
start_facecolor='w',
start_edgewidth=2,
final_style='o',
final_facecolor='k',
final_edgewidth=2)
# plot distance constraint
fig.sp.plot_fun(func=self._rescaled_distance,
multipoint=True,
plot_background=False,
n_grid_points=20,
levels_color='w',
grid_limits=ds_bounds,
levels=[0],
colorbar=False,
levels_style=':',
levels_linewidth=2.0,
alpha_levels=.5,
c=x0,
r=dmax)
fig.sp.plot_fun(lambda z: eva._objective_function(z),
multipoint=True,
grid_limits=ds_bounds,
colorbar=False,
n_grid_points=20,
plot_levels=False)
fig.sp.grid(linestyle='--', alpha=.5, zorder=0)
fig.subplot(2, 2, 3)
if self.y_target is not None:
fig.sp.title("Classifier Score for Target Class (Targ. Evasion)")
else:
fig.sp.title("Classifier Score for True Class (Indiscr. Evasion)")
fig.sp.plot(scores)
fig.sp.grid()
fig.sp.xlim(0, dmax)
fig.sp.xlabel("dmax")
fig.subplot(2, 2, 4)
fig.sp.title("Objective Function")
fig.sp.plot(f_seq)
fig.sp.grid()
fig.sp.xlim(0, dmax)
fig.sp.xlabel("dmax")
fig.tight_layout()
k_name = self.kernel.class_type if self.kernel is not None else 'lin'
fig.savefig(
fm.join(
self.images_folder,
"pgd_ls_multiclass_{:}c_kernel-{:}_target-{:}.pdf".format(
self.ds.num_classes, k_name, self.y_target)))
def _rescaled_distance(self, x, c, r):
"""Rescale distance for plot."""
if self.normalizer is not None:
c = self.normalizer.inverse_transform(c)
x = self.normalizer.inverse_transform(x)
constr = CConstraintL2(center=c, radius=r)
return x.apply_along_axis(constr.constraint, axis=1)
def _get_style(self):
"""Define the style vector for the different classes."""
if self.ds.num_classes == 3:
styles = [('b', 'o', '-'), ('g', 'p', '--'), ('r', 's', '-.')]
elif self.ds.num_classes == 4:
styles = [('saddlebrown', 'o', '-'), ('g', 'p', '--'),
('y', 's', '-.'), ('gray', 'D', '--')]
else:
styles = [('saddlebrown', 'o', '-'), ('g', 'p', '--'),
('y', 's', '-.'), ('gray', 'D', '--'), ('c', '-.'),
('m', '-'), ('y', '-.')]
return styles
def _plot_decision_function(self, fig, plot_background=False):
"""Plot the decision function of a multiclass classifier."""
fig.sp.title('{:} ({:})'.format(self.multiclass.__class__.__name__,
self.multiclass.classifier.__name__))
x_bounds, y_bounds = self.ds.get_bounds()
styles = self._get_style()
for c_idx, c in enumerate(self.ds.classes):
fig.sp.scatter(self.ds.X[self.ds.Y == c, 0],
self.ds.X[self.ds.Y == c, 1],
s=20,
c=styles[c_idx][0],
edgecolors='k',
facecolors='none',
linewidths=1,
label='c {:}'.format(c))
# Plotting multiclass decision function
fig.sp.plot_fun(lambda x: self.multiclass.predict(x),
multipoint=True,
cmap='Set2',
grid_limits=self.ds.get_bounds(offset=5),
colorbar=False,
n_grid_points=300,
plot_levels=True,
plot_background=plot_background,
levels=[-1, 0, 1, 2],
levels_color='gray',
levels_style='--')
fig.sp.xlim(x_bounds[0] - .05, x_bounds[1] + .05)
fig.sp.ylim(y_bounds[0] - .05, y_bounds[1] + .05)
fig.sp.legend(loc=9, ncol=5, mode="expand", handletextpad=.1)
return fig
