Question

我正在使用LibSVM为我的大学使用C ++支持向量机。为此，我希望能够解析充满文档和标签的.csv文件。这到目前为止工作得很好，但作为输出我得到

C = nan
obj = nan, rho = nan
nSV = 0, nBSV = 0
Total nSV = 0

这看起来好像没有生成好的数据。

我打赌我犯了一个初学者的错误但却无法弄清楚出了什么问题。下面显示了我如何创建节点，以及我使用的Document类，它应该被分析。

class Document {
public:
    double docID;
    double label;
    std::string text;
    Document(double docID, double label, std::string aText);
}

...

std::vector<Feature> features = getFeatures();
documents = getDocuments();

int documentCount = documents.size();
int featureCount = features.size();
svm_node** nodesList = new svm_node*[documentCount];
double* labelList = new double[documentCount];

for (int j = 0; j < documentCount; j++){
        nodesList[j] = new svm_node[featureCount];
        Document currentDocument = documents[j];
        for (int i = 0; i < featureCount; i++) {
            svm_node node;
            node.index = i + 1;
            node.value = features[i].analyse(currentDocument.docID);
            nodesList[j][i] = node;
        }
        labelList[j] = currentDocument.label;
    }

problem->l = documentCount;
problem->x = nodesList;
problem->y = labelList;

param->svm_type = NU_SVC;
param->kernel_type = LINEAR;
param->degree = 3;
param->gamma = 0.0625;
param->coef0 = 0;
param->nu = 0.25;
param->cache_size = 100;
param->C = 1;
param->eps = 1e-3;
param->p = 0.1;
param->shrinking = 1;
param->probability = 0;
param->nr_weight = 0;
param->weight = new double[2];
param->weight_label = new int[2];
param->weight[0] = 1;
param->weight_label[0] = 1;
param->weight[1] = 1;
param->weight_label[1] = 1;

svm_check_parameter(problem, param);
model = svm_train(problem, param);

有人知道输出无意义的原因在哪里吗？

提前谢谢！

Answer 1

检查您的功能文件，一切都是有序的吗？没有nan，inf或者非常大的数字？
您的训练数据是否有偏差？也就是说，你有一个类的很多值，但是对于另一个类几乎没有。

LibSVM无意义的输出

1 个答案: