软件版本:2018a和2014b
存在的问题：运行SVM主程序时，提示错误使用 plot；向量长度必须相同。
出错 main (line 68)
plot(1:length(test_label),predict_label_2,'b:o')
代码如下：
%% 支持向量机的分类——基于乳腺组织电阻抗特性的乳腺癌诊断
%% 清空环境变量
clear all
clc
%% 导入数据
load data1
%% 数据归一化
[Train_matrix,PS] = mapminmax(train_matrix');
Train_matrix = Train_matrix';
Test_matrix = mapminmax('apply',test_matrix',PS);
Test_matrix = Test_matrix';
%% SVM创建/训练(RBF核函数)
% 寻找最佳c/g参数——交叉验证方法
[c,g] = meshgrid(-10:0.2:10,-10:0.2:10);
[m,n] = size(c);
cg = zeros(m,n);
eps = 10^(-4);
v = 5;
bestc = 1;
bestg = 0.1;
bestacc = 0;
for i = 1:m
for j = 1:n
cmd = ['-v ',num2str(v),' -t 2',' -c ',num2str(2^c(i,j)),' -g ',num2str(2^g(i,j))];
cg(i,j) = svmtrain(train_label,Train_matrix,cmd); %%
if cg(i,j) > bestacc
bestacc = cg(i,j);
bestc = 2^c(i,j);
bestg = 2^g(i,j);
end
if abs( cg(i,j)-bestacc )<=eps && bestc > 2^c(i,j)
bestacc = cg(i,j);
bestc = 2^c(i,j);
bestg = 2^g(i,j);
end
end
end
cmd = [' -t 2',' -c ',num2str(bestc),' -g ',num2str(bestg)];
% 创建/训练SVM模型
model = svmtrain(train_label,Train_matrix,cmd);%%
%model = fitcsvm(train_label,Train_matrix,cmd);
%% SVM仿真测试
[predict_label_1,accuracy_1] = svmpredict(train_label,Train_matrix,model)
[predict_label_2,accuracy_2] = svmpredict(test_label,Test_matrix,model)
result_1 = [train_label predict_label_1]
result_2 = [test_label predict_label_2]
%% 绘图
figure
plot(1:length(test_label),test_label,'r-*')
hold on
plot(1:length(test_label),predict_label_2,'b:o')
%plot(1:length(predict_label_2),predict_label_2,'b:o')%
grid on
legend('真实类别','预测类别')
xlabel('测试集样本编号')
ylabel('测试集样本类别')
string = {'测试集SVM预测结果对比(RBF核函数)';
['accuracy = ' num2str(accuracy_2(1)) '%']};
title(string)
