SubspaceAlignedClassifier.subspace_alignment() - Code Metrics - Inspection of "Added sphinx and readthedocs." - wmkouw/libTLDA - Measure and Improve Code Quality continuously with Scrutinizer

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by Wouter

created 2018-06-17 15:54 UTC

SubspaceAlignedClassifier.subspace_alignment() B

↳ Parent: SubspaceAlignedClassifier

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Duplication

Lines	0
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Code Coverage

Tests	8
CRAP Score	2.0054

Importance

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Metric	Value
cc	2
c	0
b	0
f	0
dl	0
loc	40
ccs	8
cts	9
cp	0.8889
crap	2.0054
rs	8.8571

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import numpy as np
import scipy.stats as st
from scipy.sparse.linalg import eigs
from scipy.spatial.distance import cdist
import sklearn as sk
from sklearn.decomposition import PCA
from sklearn.svm import LinearSVC
from sklearn.linear_model import LogisticRegression, LinearRegression
from sklearn.model_selection import cross_val_predict
from os.path import basename

from .util import is_pos_def


class SubspaceAlignedClassifier(object):
    """
    Class of classifiers based on Subspace Alignment.

    Methods contain the alignment itself, classifiers and general utilities.

    Examples
    --------
    | >>>> X = np.random.randn(10, 2)
    | >>>> y = np.vstack((-np.ones((5,)), np.ones((5,))))
    | >>>> Z = np.random.randn(10, 2)
    | >>>> clf = SubspaceAlignedClassifier()
    | >>>> clf.fit(X, y, Z)
    | >>>> preds = clf.predict(Z)
    """

    def __init__(self, loss='logistic', l2=1.0, num_components=1):

        """
        Select a particular type of subspace aligned classifier.

        Parameters
        ----------
        loss : str
            loss function for weighted classifier, options: 'logistic',
            'quadratic', 'hinge' (def: 'logistic')
        l2 : float
            l2-regularization parameter value (def:0.01)
        num_components : int
            number of transfer components to maintain (def: 1)

        Returns
        -------
        None

        """
        self.loss = loss
        self.l2 = l2
        self.num_components = num_components

        # Initialize untrained classifiers
        if self.loss == 'logistic':
            # Logistic regression model
            self.clf = LogisticRegression()
        elif self.loss == 'quadratic':
            # Least-squares model
            self.clf = LinearRegression()
        elif self.loss == 'hinge':
            # Linear support vector machine
            self.clf = LinearSVC()
        else:
            # Other loss functions are not implemented
            raise NotImplementedError('Loss function not implemented.')

        # Whether model has been trained
        self.is_trained = False

        # Dimensionality of training data
        self.train_data_dim = ''

    def subspace_alignment(self, X, Z, num_components=1):
        """
        Compute subspace and alignment matrix.

        Parameters
        ----------
        X : array
            source data set (N samples by D features)
        Z : array
            target data set (M samples by D features)
        num_components : int
            number of components (def: 1)

        Returns
        -------
        V : array
            transformation matrix (D features by D features)
        CX : array
            source principal component coefficients
        CZ : array
            target principal component coefficients

        """
        # Data shapes
        N, DX = X.shape
        M, DZ = Z.shape

        # Assert equivalent dimensionalities
        if not DX == DZ:
            raise ValueError('Dimensionalities of X and Z should be equal.')

        # Compute principal components
        CX = PCA(n_components=num_components, whiten=True).fit(X).components_.T
        CZ = PCA(n_components=num_components, whiten=True).fit(Z).components_.T

        # Aligned source components
        V = np.dot(CX.T, CZ)

        # Return transformation matrix and principal component coefficients
        return V, CX, CZ

    def fit(self, X, y, Z):
        """
        Fit/train a classifier on data mapped onto transfer components.

        Parameters
        ----------
        X : array
            source data (N samples by D features)
        y : array
            source labels (N samples by 1)
        Z : array
            target data (M samples by D features)

        Returns
        -------
        None

        """
        # Data shapes
        N, DX = X.shape
        M, DZ = Z.shape

        # Assert equivalent dimensionalities
        if not DX == DZ:
            raise ValueError('Dimensionalities of X and Z should be equal.')

        # Transfer component analysis
        V, CX, CZ = self.subspace_alignment(X, Z,
                                            num_components=self.num_components)

        # Store target subspace
        self.target_subspace = CZ

        # Map source data onto source principal components
        X = np.dot(X, CX)

        # Align source data to target subspace
        X = np.dot(X, V)

        # Train a weighted classifier
        if self.loss == 'logistic':
            # Logistic regression model with sample weights
            self.clf.fit(X, y)
        elif self.loss == 'quadratic':
            # Least-squares model with sample weights
            self.clf.fit(X, y)
        elif self.loss == 'hinge':
            # Linear support vector machine with sample weights
            self.clf.fit(X, y)
        else:
            # Other loss functions are not implemented
            raise NotImplementedError

        # Mark classifier as trained
        self.is_trained = True

        # Store training data dimensionality
        self.train_data_dim = DX

    def predict(self, Z, whiten=False):

        """
        Make predictions on new dataset.

        Parameters
        ----------
        Z : array
            new data set (M samples by D features)
        whiten : boolean
            whether to whiten new data (def: false)

        Returns
        -------
        preds : array
            label predictions (M samples by 1)

        """
        # Data shape
        M, D = Z.shape

        # If classifier is trained, check for same dimensionality
        if self.is_trained:
            if not self.train_data_dim == D:
                raise ValueError('''Test data is of different dimensionality
                                 than training data.''')

        # Check for need to whiten data beforehand
        if whiten:
            Z = st.zscore(Z)

        # Map new target data onto target subspace
        Z = np.dot(Z, self.target_subspace)

        # Call scikit's predict function
        preds = self.clf.predict(Z)

        # For quadratic loss function, correct predictions
        if self.loss == 'quadratic':
            preds = (np.sign(preds)+1)/2.

        # Return predictions array
        return preds

    def get_params(self):
        """Get classifier parameters."""
        return self.clf.get_params()

    def is_trained(self):
        """Check whether classifier is trained."""
        return self.is_trained


1			#!/usr/bin/env python
2			# -- coding: utf-8 --
3
4	1		import numpy as np
5	1		import scipy.stats as st
6	1		from scipy.sparse.linalg import eigs
7	1		from scipy.spatial.distance import cdist
8	1		import sklearn as sk
9	1		from sklearn.decomposition import PCA
10	1		from sklearn.svm import LinearSVC
11	1		from sklearn.linear_model import LogisticRegression, LinearRegression
12	1		from sklearn.model_selection import cross_val_predict
13	1		from os.path import basename
14
15	1		from .util import is_pos_def
16
17
18	1		class SubspaceAlignedClassifier(object):
19			"""
20			Class of classifiers based on Subspace Alignment.
21
22			Methods contain the alignment itself, classifiers and general utilities.
23
24			Examples
25			--------
26			\| >>>> X = np.random.randn(10, 2)
27			\| >>>> y = np.vstack((-np.ones((5,)), np.ones((5,))))
28			\| >>>> Z = np.random.randn(10, 2)
29			\| >>>> clf = SubspaceAlignedClassifier()
30			\| >>>> clf.fit(X, y, Z)
31			\| >>>> preds = clf.predict(Z)
32			"""
33
34	1	View Code Duplication	def __init__(self, loss='logistic', l2=1.0, num_components=1):
			0 ignored issues – show Duplication introduced 2018-06-14 07:43 UTC by Report Bug Copy Issue Report This code seems to be duplicated in your project. Loading history...
35			"""
36			Select a particular type of subspace aligned classifier.
37
38			Parameters
39			----------
40			loss : str
41			loss function for weighted classifier, options: 'logistic',
42			'quadratic', 'hinge' (def: 'logistic')
43			l2 : float
44			l2-regularization parameter value (def:0.01)
45			num_components : int
46			number of transfer components to maintain (def: 1)
47
48			Returns
49			-------
50			None
51
52			"""
53	1		self.loss = loss
54	1		self.l2 = l2
55	1		self.num_components = num_components
56
57			# Initialize untrained classifiers
58	1		if self.loss == 'logistic':
59			# Logistic regression model
60	1		self.clf = LogisticRegression()
61			elif self.loss == 'quadratic':
62			# Least-squares model
63			self.clf = LinearRegression()
64			elif self.loss == 'hinge':
65			# Linear support vector machine
66			self.clf = LinearSVC()
67			else:
68			# Other loss functions are not implemented
69			raise NotImplementedError('Loss function not implemented.')
70
71			# Whether model has been trained
72	1		self.is_trained = False
73
74			# Dimensionality of training data
75	1		self.train_data_dim = ''
76
77	1		def subspace_alignment(self, X, Z, num_components=1):
78			"""
79			Compute subspace and alignment matrix.
80
81			Parameters
82			----------
83			X : array
84			source data set (N samples by D features)
85			Z : array
86			target data set (M samples by D features)
87			num_components : int
88			number of components (def: 1)
89
90			Returns
91			-------
92			V : array
93			transformation matrix (D features by D features)
94			CX : array
95			source principal component coefficients
96			CZ : array
97			target principal component coefficients
98
99			"""
100			# Data shapes
101	1		N, DX = X.shape
102	1		M, DZ = Z.shape
103
104			# Assert equivalent dimensionalities
105	1		if not DX == DZ:
106			raise ValueError('Dimensionalities of X and Z should be equal.')
107
108			# Compute principal components
109	1		CX = PCA(n_components=num_components, whiten=True).fit(X).components_.T
110	1		CZ = PCA(n_components=num_components, whiten=True).fit(Z).components_.T
111
112			# Aligned source components
113	1		V = np.dot(CX.T, CZ)
114
115			# Return transformation matrix and principal component coefficients
116	1		return V, CX, CZ
117
118	1		def fit(self, X, y, Z):
119			"""
120			Fit/train a classifier on data mapped onto transfer components.
121
122			Parameters
123			----------
124			X : array
125			source data (N samples by D features)
126			y : array
127			source labels (N samples by 1)
128			Z : array
129			target data (M samples by D features)
130
131			Returns
132			-------
133			None
134
135			"""
136			# Data shapes
137	1		N, DX = X.shape
138	1		M, DZ = Z.shape
139
140			# Assert equivalent dimensionalities
141	1		if not DX == DZ:
142			raise ValueError('Dimensionalities of X and Z should be equal.')
143
144			# Transfer component analysis
145	1		V, CX, CZ = self.subspace_alignment(X, Z,
146			num_components=self.num_components)
147
148			# Store target subspace
149	1		self.target_subspace = CZ
150
151			# Map source data onto source principal components
152	1		X = np.dot(X, CX)
153
154			# Align source data to target subspace
155	1		X = np.dot(X, V)
156
157			# Train a weighted classifier
158	1		if self.loss == 'logistic':
159			# Logistic regression model with sample weights
160	1		self.clf.fit(X, y)
161			elif self.loss == 'quadratic':
162			# Least-squares model with sample weights
163			self.clf.fit(X, y)
164			elif self.loss == 'hinge':
165			# Linear support vector machine with sample weights
166			self.clf.fit(X, y)
167			else:
168			# Other loss functions are not implemented
169			raise NotImplementedError
170
171			# Mark classifier as trained
172	1		self.is_trained = True
173
174			# Store training data dimensionality
175	1		self.train_data_dim = DX
176
177	1	View Code Duplication	def predict(self, Z, whiten=False):
			0 ignored issues – show Duplication introduced 2018-06-17 15:58 UTC by Report Bug Copy Issue Report This code seems to be duplicated in your project. Loading history...
178			"""
179			Make predictions on new dataset.
180
181			Parameters
182			----------
183			Z : array
184			new data set (M samples by D features)
185			whiten : boolean
186			whether to whiten new data (def: false)
187
188			Returns
189			-------
190			preds : array
191			label predictions (M samples by 1)
192
193			"""
194			# Data shape
195	1		M, D = Z.shape
196
197			# If classifier is trained, check for same dimensionality
198	1		if self.is_trained:
199	1		if not self.train_data_dim == D:
200			raise ValueError('''Test data is of different dimensionality
201			than training data.''')
202
203			# Check for need to whiten data beforehand
204	1		if whiten:
205			Z = st.zscore(Z)
206
207			# Map new target data onto target subspace
208	1		Z = np.dot(Z, self.target_subspace)
209
210			# Call scikit's predict function
211	1		preds = self.clf.predict(Z)
212
213			# For quadratic loss function, correct predictions
214	1		if self.loss == 'quadratic':
215			preds = (np.sign(preds)+1)/2.
216
217			# Return predictions array
218	1		return preds
219
220	1		def get_params(self):
221			"""Get classifier parameters."""
222			return self.clf.get_params()
223
224	1		def is_trained(self):
225			"""Check whether classifier is trained."""
226			return self.is_trained
227

wmkouw / libTLDA

Push — master ( f3d068...88fa67 )

SubspaceAlignedClassifier.subspace_alignment() B

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