predict.naiveBayes {e1071} | R Documentation |
Computes the conditional a-posterior probabilities of a categorical class variable given independent predictor variables using the Bayes rule.
predict.naiveBayes(object, newdata, type = c("class", "raw"), threshold = 0.001, ...)
object |
An object of class "naiveBayes" . |
newdata |
A dataframe with new predictors. |
type |
see value. |
threshold |
Value replacing cells with 0 probabilities. |
... |
Currently not used. |
The standard naive Bayes classifier (at least this implementation) assumes independence of the predictor variables, and gaussian distribution (given the target class) of metric predictors. For attributes with missing values, the corresponding table entries are omitted for prediction.
If type = "raw"
, the conditional a-posterior
probabilities for each class are returned, and the class with
maximal probability else.
David Meyer David.Meyer@R-project.org
## Categorical data only: data(HouseVotes84) model <- naiveBayes(Class ~ ., data = HouseVotes84) predict(model, HouseVotes84[1:10,-1]) predict(model, HouseVotes84[1:10,-1], type = "raw") pred <- predict(model, HouseVotes84[,-1]) table(pred, HouseVotes84$Class) ## Example of using a contingency table: data(Titanic) m <- naiveBayes(Survived ~ ., data = Titanic) m predict(m, as.data.frame(Titanic)[,1:3]) ## Example with metric predictors: data(iris) m <- naiveBayes(Species ~ ., data = iris) ## alternatively: m <- naiveBayes(iris[,-5], iris[,5]) m table(predict(m, iris[,-5]), iris[,5])