Files
TSVMs/UTSVM.py
2025-11-08 08:53:32 +01:00

146 lines
5.3 KiB
Python
Executable File

"""
Article : Twin Support Vector Machine with Universum data
Link : https://sci-hub.tw/https://www.sciencedirect.com/science/article/abs/pii/S0893608012002304
Author : Saeed Khosravi
"""
import numpy as np
from cvxopt import solvers, matrix
class UTSVM:
def __init__(self, X, y, U, C1, C2, CU, eps):
self.X = X
self.y = y
self.U = U
self.C1 = C1
self.C2 = C2
self.CU = CU
self.eps = eps
def fit(self):
self.w1, self.b1 = self.plane1(self.X, self.y, self.U, self.C1, self.CU, self.eps)
self.w2, self.b2 = self.plane2(self.X, self.y, self.U, self.C2, self.CU, self.eps)
def predict(self, x_test):
norm2_w1 = np.linalg.norm(self.w1)
norm2_w2 = np.linalg.norm(self.w2)
distance_1 = np.abs(np.dot(x_test, self.w1) + self.b1)/norm2_w1
distance_2 = np.abs(np.dot(x_test, self.w2) + self.b2)/norm2_w2
y_pred = np.zeros_like(distance_1).reshape((-1, 1))
for i in range(y_pred.shape[0]):
if (distance_1[i] < distance_2[i]):
y_pred[i][0] = 1;
else:
y_pred[i][0] = -1;
self.preds = y_pred
def plane1(self, X, y, U, c, cu, eps):
A = X[np.ix_(y[:,0] == 1),:][0,:,:]
B = X[np.ix_(y[:,0] == -1),:][0,:,:]
m1 = A.shape[0]
m2 = B.shape[0]
ep = np.ones((m1, 1))
en = np.ones((m2, 1))
mu = U.shape[0]
eu = np.ones((mu, 1))
H = np.concatenate((A, ep), axis = 1)
G = np.concatenate((B, en), axis = 1)
O = np.concatenate((U, eu), axis = 1)
HTH = np.dot(H.T, H)
I = np.eye(HTH.shape[0], HTH.shape[1])
HTH_inv = np.linalg.inv(1e-4*I + HTH)
_P = np.dot(np.dot(G, HTH_inv), G.T)
_P = np.concatenate((_P, -np.dot(np.dot(G, HTH_inv), O.T)), axis = 1)
_P2 = -np.dot(np.dot(O, HTH_inv), G.T)
_P2 = np.concatenate((_P2, np.dot(np.dot(O, HTH_inv), O.T)), axis = 1)
_P = np.concatenate((_P, _P2), axis = 0) # (en + eu , en + eu)
_q = np.concatenate((-en.T, (1-eps)*eu.T), axis = 1).T # (en + eu , 1)
_G1 = np.concatenate(( np.eye(m2, m2), np.zeros((m2, mu))), axis = 1)
_G2 = np.concatenate((-np.eye(m2, m2), np.zeros((m2, mu))), axis = 1)
_G3 = np.concatenate(( np.zeros((mu, m2)), np.eye(mu, mu)), axis = 1)
_G4 = np.concatenate(( np.zeros((mu, m2)), -np.eye(mu, mu)), axis = 1)
_G = np.concatenate((_G1, _G2), axis = 0)
_G = np.concatenate((_G , _G3), axis = 0)
_G = np.concatenate((_G, _G4), axis = 0) # (4 * m2, m2 + mu)
_h = np.zeros((2*m2 + 2*mu, 1))
_h[:m2, 0] = c
_h[2*m2:2*m2+mu, :] = cu
_P = matrix(_P, tc= 'd')
_q = matrix(_q, tc = 'd')
_G = matrix(_G, tc = 'd')
_h = matrix(_h, tc = 'd')
qp_sol = solvers.qp(_P, _q, _G, _h, kktsolver='ldl', options={'kktreg':1e-9, 'show_progress':False})
qp_sol = np.array(qp_sol['x'])
alphas = qp_sol[:m2, 0]
mus = qp_sol[m2:, 0]
vp = -np.dot(HTH_inv, np.dot(G.T, alphas) - np.dot(O.T, mus))
w = vp[:vp.shape[0]-1]
b = vp[vp.shape[0]-1]
return w, b
def plane2(self, X, y, U, c, cu, eps):
A = X[np.ix_(y[:,0] == -1),:][0,:,:]
B = X[np.ix_(y[:,0] == 1),:][0,:,:]
m1 = A.shape[0]
m2 = B.shape[0]
en = np.ones((m1, 1))
ep = np.ones((m2, 1))
mu = U.shape[0]
eu = np.ones((mu, 1))
Q = np.concatenate((A, en), axis = 1)
P = np.concatenate((B, ep), axis = 1)
S = np.concatenate((U, eu), axis = 1)
QTQ = np.dot(Q.T, Q)
I = np.eye(QTQ.shape[0], QTQ.shape[1])
QTQ_inv = np.linalg.inv(1e-4*I + QTQ)
_P = np.dot(np.dot(P, QTQ_inv), P.T)
_P = np.concatenate((_P, -np.dot(np.dot(P, QTQ_inv), S.T)), axis = 1)
_P2 = -np.dot(np.dot(S, QTQ_inv), P.T)
_P2 = np.concatenate((_P2, np.dot(np.dot(S, QTQ_inv), S.T)), axis = 1)
_P = np.concatenate((_P, _P2), axis = 0) # (ep + eu , ep + eu)
_q = np.concatenate((-ep.T, (1-eps)*eu.T), axis = 1).T # (ep + eu , 1)
_G1 = np.concatenate(( np.eye(m2, m2), np.zeros((m2, mu))), axis = 1)
_G2 = np.concatenate((-np.eye(m2, m2), np.zeros((m2, mu))), axis = 1)
_G3 = np.concatenate(( np.zeros((mu, m2)), np.eye(mu, mu)), axis = 1)
_G4 = np.concatenate(( np.zeros((mu, m2)), -np.eye(mu, mu)), axis = 1)
_G = np.concatenate((_G1, _G2), axis = 0)
_G = np.concatenate((_G , _G3), axis = 0)
_G = np.concatenate((_G, _G4), axis = 0) # (4 * m2, m2 + mu)
_h = np.zeros((2*m2 + 2*mu, 1))
_h[:m2, 0] = c
_h[2*m2:2*m2+mu, :] = cu
_P = matrix(_P, tc= 'd')
_q = matrix(_q, tc = 'd')
_G = matrix(_G, tc = 'd')
_h = matrix(_h, tc = 'd')
qp_sol = solvers.qp(_P, _q, _G, _h, kktsolver='ldl', options={'kktreg':1e-9, 'show_progress':False})
qp_sol = np.array(qp_sol['x'])
alphas = qp_sol[:m2, 0]
mus = qp_sol[m2:, 0]
vp = -np.dot(QTQ_inv, np.dot(P.T, alphas) - np.dot(S.T, mus))
w = vp[:vp.shape[0]-1]
b = vp[vp.shape[0]-1]
return w, b
def get_params(self):
return self.w1, self.b1, self.w2, self.b2
def get_preds(self):
return self.preds