machine learning - How to find the Precision, Recall, Accuracy using SVM? -

duplicate calculating precision, recall , f score

i have input file text description , classified level (i.e.levela , levelb). want write svm classifier measure precision, recall , accuracy. looked @ scikit , libsvm want know more step step.

any sample code or basic tutorial nice. suggestion in advance.

these performance measures easy obtain predicted labels , true labels, post-processing step:

1. precision = tp / (tp+fp)
2. recall = tp / (tp+fn)
3. accuracy = (tp + tn) / (tp + tn + fp + fn)

with tp, fp, tn, fn being number of true positives, false positives, true negatives , false negatives, respectively.