python簡單實現感知機對偶形式
阿新 • • 發佈:2019-02-17
完全對照統計學習方法
from numpy import *
data_set=array([[[3,3],1],[[4,3],1],[[1,1],-1]])
eta=1
n=len(data_set)
gram=zeros((n,n))
a=[0,0,0]
b=0
def cal_gram(data_set):
for i in range(len(data_set)):
for j in range(len(data_set)):
gram[i][j]=data_set[i][0][0]*data_set[j][0][0]+data_set[i][0][1]*data_set[j][0 ][1]
return gram
def f(x):
ans=0
for j in range(len(data_set)):
ans+=a[j]*gram[x][j]*data_set[j][1]
ans+=b
return ans
def perception(data_set):
global b
flag=True
for i in range(len(data_set)):
if data_set[i][1]*f(i)<=0:
flag=False
a[i]+=eta
b+=eta*data_set[i][1 ]
if flag==False:
perception(data_set)
cal_gram(data_set)
print(gram)
perception(data_set)
print(a,b)