# What threshold generates the accuracy calculated by a SVM classifier in Matlab's libsvm?

When we use SVM to do classification, we usually will use this kind of code:

[predict_label,accuracy,decision]=svmpredict(testlabel,testdata,model);

We all know the classifier was using probability to make sure if the predict_label is positive or negative, which is according to thresholds. And with each threshold, we can get a group of sensitivity and specificity, thus we can draw an ROC curve.

My question is the accuracy from the output, we always get a specific number, which is also called ACC. So which threshold is this specific number based on?

The reported accuracy is for the default threshold of $0.0$.