singlenativebayes.m

朴素贝叶斯matlab实现

%输入训练集和一条测试列，输出该列的分类类别
function y=singleNativebayes(train,singletest)
[row col]=size(train);
y=[];
c1=0;
c2=0;
Sum1=1;
Sum2=1;
for i=1:col-1
m1(i)=0;
m2(i)=0;
end
for i=1:row
    if train(i,col)==2
        c1=c1+1;
    end
    if train(i,col)==4
     c2=c2+1;
    end   
    for j=1:col-1
        if train(i,j)==singletest(j)&train(i,col)==2
            m1(j)=m1(j)+1;
        end
        if train(i,j)==singletest(j)&train(i,col)==4
            m2(j)=m2(j)+1;
        end        
    end
end
for j=1:col-1
       if m1(j)==0
        m1(j)=0.1;
       end
    if m2(j)==0
        m2(j)=0.1;
    end
  
end
for k=1:col-1
    if c1==0
        Sum1=0;
    else
    Sum1=Sum1*m1(k)/c1;
    end
    if c2==0
        Sum2=0;
    else
    Sum2=Sum2*m2(k)/c2;
    end
 end
Sum1=Sum1*c1/(c1+c2);
Sum2=Sum2*c2/(c1+c2);
if Sum1>Sum2
    y=2;
else
    y=4;
end