MATLAB中的10倍SVM分类示例
我需要一个描述性的例子来说明如何在两类数据集上进行10倍的SVM分类。 在MATLAB文档中只有一个例子，但不是10倍。 有人能帮我吗？
这是一个完整的例子，使用生物信息学工具箱中的以下function： SVMTRAIN ， SVMCLASSIFY ， CLASSPERF ， CROSSVALIND 。
load fisheriris %# load iris dataset groups = ismember(species,'setosa'); %# create a two-class problem %# number of cross-validation folds: %# If you have 50 samples, divide them into 10 groups of 5 samples each, %# then train with 9 groups (45 samples) and test with 1 group (5 samples). %# This is repeated ten times, with each group used exactly once as a test set. %# Finally the 10 results from the folds are averaged to produce a single %# performance estimation. k=10; cvFolds = crossvalind('Kfold', groups, k); %# get indices of 10-fold CV cp = classperf(groups); %# init performance tracker for i = 1:k %# for each fold testIdx = (cvFolds == i); %# get indices of test instances trainIdx = ~testIdx; %# get indices training instances %# train an SVM model over training instances svmModel = svmtrain(meas(trainIdx,:), groups(trainIdx), ... 'Autoscale',true, 'Showplot',false, 'Method','QP', ... 'BoxConstraint',2e-1, 'Kernel_Function','rbf', 'RBF_Sigma',1); %# test using test instances pred = svmclassify(svmModel, meas(testIdx,:), 'Showplot',false); %# evaluate and update performance object cp = classperf(cp, pred, testIdx); end %# get accuracy cp.CorrectRate %# get confusion matrix %# columns:actual, rows:predicted, last-row: unclassified instances cp.CountingMatrix 与输出：
ans = 0.99333 ans = 100 1 0 49 0 0
我们获得了99.33%准确性，只有一个“setosa”实例被误分类为“非setosa”
更新 ：SVMfunction已经转移到R2013a统计工具箱
