I am using PyML for SVM classification. However, I noticed that when I evaluate a multi-class classifier using LOO, the results object does not report the sensitivity and PPV values. Instead they are 0.0:
from PyML import *
from PyML.classifiers import multi
mc = multi.OneAgainstRest(SVM())
data = VectorDataSet('iris.data', labelsColumn=-1)
result = mc.loo(data)
result.getSuccessRate()
>>> 0.95333333333333337
result.getPPV()
>>> 0.0
result.getSensitivity()
>>> 0.0
I have looked at the code but couldn't figure out what is going wrong here. Has somebody a workaround for this?