performance
measures difference between predictions and data
performance(results, outcome, measure)
Arguments
results |
Numeric vector with predictions |
outcome |
Numeric vector same length as results with real data to compare to. |
measure |
Optional length one character vector that is either:
"accuracy", "sens", "spec", or "ppv". This specifies what measure of
predictive performance to use for training and evaluating the model. The
default measure is "accuracy" . However, accuracy can be a problematic
measure when the classes are imbalanced in the samples, i.e. if a class the
model is trying to predict is very rare. Alternatives to accuracy are
available that illuminate different aspects of predictive power. Sensitivity
answers the question, `` given that a result is truly an event, what is the
probability that the model will predict an event?'' Specificity answers the
question, ``given that a result is truly not an event, what is the
probability that the model will predict a negative?'' Positive predictive
value answers, ``what is the percent of predicted positives that are
actually positive?'' |
Value
Returns a numeric vector length one.
Details
This is the function of the datafsm package used to measure the fsm model performance. It uses the caret package.