Explicitly listing probabilities in a classification task
I am using RapidMiner with a database of medical information to estimate the probability that a patient will be diagnosed with a certain class of ailment (eg. gastrointestinal, cancer, respiratory) based on their sociodemographic data. My dataset contains almost one million records, with each record representing a patient. For each patient and each ailment category, I have the label "true" if the patient has been diagnosed with an ailment in this category, and "false" if they have not been.
What I would like RapidMiner to do, is to learn the classification rules from a training set, and then return the probability that a record belongs to the classification group "true" for each record in the test set. I have found many useful tools for performing the classification, but I can't find a routine that will tell me the value of P(true) after everything else is said and done. If anyone has any suggestions about how to do this, I would be very grateful. Thanks in advance!