Skip to content

Commit

Permalink
add SVM SMO and QP
Browse files Browse the repository at this point in the history
  • Loading branch information
junlulocky committed Jul 28, 2017
1 parent 131ffda commit e426ffd
Show file tree
Hide file tree
Showing 18 changed files with 952 additions and 1 deletion.
22 changes: 22 additions & 0 deletions .gitignore
Original file line number Diff line number Diff line change
@@ -0,0 +1,22 @@
## Core latex/pdflatex auxiliary files:
*.aux
*.lof
*.log
*.lot
*.fls
*.out
*.toc
*.fmt
*.fot
*.cb
*.cb2


## MAC
.DS_Store

## PyCharm
*.idea/*.iml

# auxiliary python files
*.pyc
7 changes: 6 additions & 1 deletion README.md
Original file line number Diff line number Diff line change
Expand Up @@ -48,6 +48,11 @@ MachineLearning

[libsvm liblinear-usage](https://github.com/wepe/MachineLearning/tree/master/SVM/libsvm%20liblinear-usage) 对使用广泛的libsvm、liblinear的使用方法进行了总结,详细介绍:[文章链接](http://blog.csdn.net/u012162613/article/details/45206813)

[SVM by SMO](./SVM/SVM_by_SMO) - 用SMO实现了SVM

[SVM by QP](./SVM/SVM_by_QP) - 用二次编程(QP)实现了SVM


- **GMM**

GMM和k-means作为EM算法的应用,在某种程度有些相似之处,不过GMM明显学习出一些概率密度函数来,结合相关理解写成python版本,详细介绍:[文章链接](http://blog.csdn.net/gugugujiawei/article/details/45583051)
Expand All @@ -72,4 +77,4 @@ MachineLearning

- [wepon](https://github.com/wepe)
- [Gogary](https://github.com/enjoyhot)
- [Locky](https://github.com/junlulocky)
7 changes: 7 additions & 0 deletions SVM/SVM_by_QP/README.md
Original file line number Diff line number Diff line change
@@ -0,0 +1,7 @@
# SVM Python

This is an example of SVM implementation by Python based on cvxopt.

The quadratic programming function, please refer to http://cvxopt.org/userguide/coneprog.html?highlight=qp#cvxopt.solvers.qp

The theory of SVM, please refer to the four SVM slides included in this project.
100 changes: 100 additions & 0 deletions SVM/SVM_by_QP/SVCQP.py
Original file line number Diff line number Diff line change
@@ -0,0 +1,100 @@
import numpy as np
from numpy import linalg
import cvxopt
import cvxopt.solvers

## define kenrel functions
def linear_kernel(x1, x2):
return np.dot(x1, x2)

def polynomial_kernel(x, y, p=3):
return (1 + np.dot(x, y)) ** p

def gaussian_kernel(x, y, sigma=5.0):
return np.exp(-linalg.norm(x-y)**2 / (2 * (sigma ** 2)))
## end define kernel functions

class SVM(object):
"""
Suppoet vector classification by quadratic programming
"""

def __init__(self, kernel=linear_kernel, C=None):
"""
:param kernel: kernel types, should be in the kernel function list above
:param C:
"""
self.kernel = kernel
self.C = C
if self.C is not None: self.C = float(self.C)

def fit(self, X, y):
n_samples, n_features = X.shape

# Gram matrix
K = np.zeros((n_samples, n_samples))
for i in range(n_samples):
for j in range(n_samples):
K[i,j] = self.kernel(X[i], X[j])

P = cvxopt.matrix(np.outer(y,y) * K)
q = cvxopt.matrix(np.ones(n_samples) * -1)
A = cvxopt.matrix(y, (1,n_samples))
b = cvxopt.matrix(0.0)

if self.C is None:
G = cvxopt.matrix(np.diag(np.ones(n_samples) * -1))
h = cvxopt.matrix(np.zeros(n_samples))
else:
tmp1 = np.diag(np.ones(n_samples) * -1)
tmp2 = np.identity(n_samples)
G = cvxopt.matrix(np.vstack((tmp1, tmp2)))
tmp1 = np.zeros(n_samples)
tmp2 = np.ones(n_samples) * self.C
h = cvxopt.matrix(np.hstack((tmp1, tmp2)))

# solve QP problem, DOC: http://cvxopt.org/userguide/coneprog.html?highlight=qp#cvxopt.solvers.qp
solution = cvxopt.solvers.qp(P, q, G, h, A, b)

# Lagrange multipliers
a = np.ravel(solution['x'])

# Support vectors have non zero lagrange multipliers
sv = a > 1e-5
ind = np.arange(len(a))[sv]
self.a = a[sv]
self.sv = X[sv]
self.sv_y = y[sv]
print "%d support vectors out of %d points" % (len(self.a), n_samples)

# Intercept
self.b = 0
for n in range(len(self.a)):
self.b += self.sv_y[n]
self.b -= np.sum(self.a * self.sv_y * K[ind[n],sv])
self.b /= len(self.a)

# Weight vector
if self.kernel == linear_kernel:
self.w = np.zeros(n_features)
for n in range(len(self.a)):
self.w += self.a[n] * self.sv_y[n] * self.sv[n]
else:
self.w = None

def project(self, X):
if self.w is not None:
return np.dot(X, self.w) + self.b
else:
y_predict = np.zeros(len(X))
for i in range(len(X)):
s = 0
for a, sv_y, sv in zip(self.a, self.sv_y, self.sv):
s += a * sv_y * self.kernel(X[i], sv)
y_predict[i] = s
return y_predict + self.b

def predict(self, X):
return np.sign(self.project(X))

Binary file added SVM/SVM_by_QP/doc/.DS_Store
Binary file not shown.
Binary file added SVM/SVM_by_QP/doc/Reference/SVM_Dual.pdf
Binary file not shown.
Binary file added SVM/SVM_by_QP/doc/Reference/SVM_Kernel.pdf
Binary file not shown.
Binary file added SVM/SVM_by_QP/doc/Reference/SVM_Primal.pdf
Binary file not shown.
Binary file added SVM/SVM_by_QP/doc/Reference/SVM_SoftMargin.pdf
Binary file not shown.
Binary file added SVM/SVM_by_QP/doc/SVM_quick_doc.pdf
Binary file not shown.
153 changes: 153 additions & 0 deletions SVM/SVM_by_QP/testSVM.py
Original file line number Diff line number Diff line change
@@ -0,0 +1,153 @@
from SVCQP import *
import pylab as pl

def gen_lin_separable_data():
# generate training data in the 2-d case
mean1 = np.array([0, 2])
mean2 = np.array([2, 0])
cov = np.array([[0.8, 0.6], [0.6, 0.8]])
X1 = np.random.multivariate_normal(mean1, cov, 100)
y1 = np.ones(len(X1))
X2 = np.random.multivariate_normal(mean2, cov, 100)
y2 = np.ones(len(X2)) * -1
return X1, y1, X2, y2

def gen_non_lin_separable_data():
mean1 = [-1, 2]
mean2 = [1, -1]
mean3 = [4, -4]
mean4 = [-4, 4]
cov = [[1.0,0.8], [0.8, 1.0]]
X1 = np.random.multivariate_normal(mean1, cov, 50)
X1 = np.vstack((X1, np.random.multivariate_normal(mean3, cov, 50)))
y1 = np.ones(len(X1))
X2 = np.random.multivariate_normal(mean2, cov, 50)
X2 = np.vstack((X2, np.random.multivariate_normal(mean4, cov, 50)))
y2 = np.ones(len(X2)) * -1
return X1, y1, X2, y2

def gen_lin_separable_overlap_data():
# generate training data in the 2-d case
mean1 = np.array([0, 2])
mean2 = np.array([2, 0])
cov = np.array([[1.5, 1.0], [1.0, 1.5]])
X1 = np.random.multivariate_normal(mean1, cov, 100)
y1 = np.ones(len(X1))
X2 = np.random.multivariate_normal(mean2, cov, 100)
y2 = np.ones(len(X2)) * -1
return X1, y1, X2, y2

def split_train(X1, y1, X2, y2):
X1_train = X1[:90]
y1_train = y1[:90]
X2_train = X2[:90]
y2_train = y2[:90]
X_train = np.vstack((X1_train, X2_train))
y_train = np.hstack((y1_train, y2_train))
return X_train, y_train

def split_test(X1, y1, X2, y2):
X1_test = X1[90:]
y1_test = y1[90:]
X2_test = X2[90:]
y2_test = y2[90:]
X_test = np.vstack((X1_test, X2_test))
y_test = np.hstack((y1_test, y2_test))
return X_test, y_test

def plot_margin(X1_train, X2_train, clf):
def f(x, w, b, c=0):
# given x, return y such that [x,y] in on the line
# w.x + b = c
return (-w[0] * x - b + c) / w[1]

pl.plot(X1_train[:,0], X1_train[:,1], "ro")
pl.plot(X2_train[:,0], X2_train[:,1], "bo")
pl.scatter(clf.sv[:,0], clf.sv[:,1], s=100, c="g")

# w.x + b = 0
a0 = -4; a1 = f(a0, clf.w, clf.b)
b0 = 4; b1 = f(b0, clf.w, clf.b)
pl.plot([a0,b0], [a1,b1], "k")

# w.x + b = 1
a0 = -4; a1 = f(a0, clf.w, clf.b, 1)
b0 = 4; b1 = f(b0, clf.w, clf.b, 1)
pl.plot([a0,b0], [a1,b1], "k--")

# w.x + b = -1
a0 = -4; a1 = f(a0, clf.w, clf.b, -1)
b0 = 4; b1 = f(b0, clf.w, clf.b, -1)
pl.plot([a0,b0], [a1,b1], "k--")

pl.axis("tight")
pl.show()

def plot_contour(X1_train, X2_train, clf):
pl.plot(X1_train[:,0], X1_train[:,1], "ro")
pl.plot(X2_train[:,0], X2_train[:,1], "bo")
pl.scatter(clf.sv[:,0], clf.sv[:,1], s=100, c="g")

X1, X2 = np.meshgrid(np.linspace(-6,6,50), np.linspace(-6,6,50))
X = np.array([[x1, x2] for x1, x2 in zip(np.ravel(X1), np.ravel(X2))])
Z = clf.project(X).reshape(X1.shape)
pl.contour(X1, X2, Z, [0.0], colors='k', linewidths=1, origin='lower')
pl.contour(X1, X2, Z + 1, [0.0], colors='grey', linewidths=1, origin='lower')
pl.contour(X1, X2, Z - 1, [0.0], colors='grey', linewidths=1, origin='lower')

pl.axis("tight")
pl.show()

def test_linear():
X1, y1, X2, y2 = gen_lin_separable_data()
X_train, y_train = split_train(X1, y1, X2, y2)
X_test, y_test = split_test(X1, y1, X2, y2)

clf = SVM()
clf.fit(X_train, y_train)

y_predict = clf.predict(X_test)
correct = np.sum(y_predict == y_test)
print "%d out of %d predictions correct" % (correct, len(y_predict))

plot_margin(X_train[y_train==1], X_train[y_train==-1], clf)

def test_non_linear():
X1, y1, X2, y2 = gen_non_lin_separable_data()
X_train, y_train = split_train(X1, y1, X2, y2)
X_test, y_test = split_test(X1, y1, X2, y2)

# X_train = np.load('inputClf/X_train.npy')
# y_train = np.load('inputClf/y_train.npy')
# X_test = np.load('inputClf/X_test.npy')
# y_test = np.load('inputClf/y_test.npy')
clf = SVM(gaussian_kernel, C=1)
clf.fit(X_train, y_train)

y_predict = clf.predict(X_test)
correct = np.sum(y_predict == y_test)
print "%d out of %d predictions correct" % (correct, len(y_predict))

plot_contour(X_train[y_train==1], X_train[y_train==-1], clf)

def test_soft():
X1, y1, X2, y2 = gen_lin_separable_overlap_data()
X_train, y_train = split_train(X1, y1, X2, y2)
X_test, y_test = split_test(X1, y1, X2, y2)



clf = SVM(C=0.1)
clf.fit(X_train, y_train)

y_predict = clf.predict(X_test)
correct = np.sum(y_predict == y_test)
print "%d out of %d predictions correct" % (correct, len(y_predict))

plot_contour(X_train[y_train==1], X_train[y_train==-1], clf)


if __name__ == "__main__":

test_non_linear()
#test_soft()
33 changes: 33 additions & 0 deletions SVM/SVM_by_SMO/README.md
Original file line number Diff line number Diff line change
@@ -0,0 +1,33 @@
# SVM

Simple implementation of a Support Vector Classification using the Sequential Minimal Optimization (SMO) algorithm for
training.

## Supported python versions:
* Python 2.7
* Python 3.4

## Python package dependencies
* Numpy

# Documentation

Setup model (following parameters are default)

```python

from SVCSMO import SVCSMO
model = SVCSMO(max_iter=10000, kernel_type='linear', C=1.0, epsilon=0.001)
```

Train model

```python
model.fit(X, y)
```

Predict new observations

```python
y_hat = model.predict(X_test)
```
Loading

0 comments on commit e426ffd

Please sign in to comment.