模式选择算法 matlab代码
时间: 2023-10-29 15:13:35 浏览: 38
模式选择算法(Pattern Selection Algorithm)是一种用于模式识别和分类的算法,其中用于分类的模式是由多个低维特征向量组成的高维模式。下面是MATLAB代码示例:
```
function [w, b, alpha] = pattern_selection_algorithm(X, Y, C)
% Input:
% X: N*M matrix, N is the number of samples, M is the number of features
% Y: N*1 vector, binary labels of samples
% C: scalar, regularization parameter
% Output:
% w: M*1 vector, separating hyperplane
% b: scalar, bias term
% alpha: N*1 vector, Lagrange multiplier
N = size(X, 1);
M = size(X, 2);
H = (X*X').*(Y*Y');
f = -ones(N, 1);
Aeq = Y';
beq = 0;
lb = zeros(N, 1);
ub = C*ones(N, 1);
alpha = quadprog(H, f, [], [], Aeq, beq, lb, ub);
w = X'*(alpha.*Y);
idx = find(alpha > 1e-4);
b = mean(Y(idx) - X(idx,:)*w);
end
```
其中,输入参数X是N个M维样本的矩阵,Y是N个样本的二元标签向量,C是正则化参数。输出参数w是分离超平面的法向量,b是偏置项,alpha是拉格朗日乘子向量。函数内部使用二次规划(quadprog)来求解拉格朗日乘子。