感知器matlab实例,感知器算法----Matlab实现

data=[0 0 -1;0 1 1 ; -1 0 1 ; 1 1 -1];

X = data(:, [1, 2]); y = data(:, 3);

m = size(X,1);

plotData2(X,y);

X = [ones(m,1) X];

error = 1;

W=[0;0;0];

first = 1;

tim=0;

alph=0.1;

hold on

axis([-2 2 -2 2]);

x1=-2:0.2:2;

while error>0

error=0;

for i = 1:m

if ( ((W'*(X(i,:)'))*y(i) <= 0 )|| (first == 1) )

first=0;

error=error+1;

tim=tim+1;

W = W + alph*(X(i,:))'*y(i);

fprintf('%dn',tim);

if W(3)~=0 && W(2)~=0

y1=-(W(1)/W(3)+W(2)*x1/W(3));

plot(x1,y1,'-b');

end;

end;

end;

end;

if W(3)~=0 && W(2)~=0

y1=-(W(1)/W(3)+W(2)*x1/W(3));

plot(x1,y1,'r');

end;

hold off

function plotData2(X, y)

figure; hold on;

pos = find(y==1) ;

neg = find(y==-1);

fprintf('%dnn',pos);

fprintf('%dn',neg);

% Plot Examples

plot(X(pos, 1), X(pos, 2), 'k+','LineWidth', 2, ...

'MarkerSize', 9);

plot(X(neg, 1), X(neg, 2), 'ko', 'MarkerFaceColor', 'r', ...

'MarkerSize', 7);

hold off;

end

效果是这样的：

权值为：

-0.100000000000000

-0.300000000000000

0.200000000000000