Given a Task, creates a model for the learning machine which can be used for predictions on new data.
Arguments
- learner
(Learner |
character(1)
)
The learner. If you pass a string the learner will be created via makeLearner.- task
(Task)
The task.- subset
(integer | logical |
NULL
)
Selected cases. Either a logical or an index vector. By defaultNULL
if all observations are used.- weights
(numeric)
Optional, non-negative case weight vector to be used during fitting. If given, must be of same length assubset
and in corresponding order. By defaultNULL
which means no weights are used unless specified in the task (Task). Weights from the task will be overwritten.
Value
(WrappedModel).
Examples
training.set = sample(seq_len(nrow(iris)), nrow(iris) / 2)
## use linear discriminant analysis to classify iris data
task = makeClassifTask(data = iris, target = "Species")
learner = makeLearner("classif.lda", method = "mle")
mod = train(learner, task, subset = training.set)
#> Error in x[0, , drop = FALSE]: incorrect number of dimensions
print(mod)
#> Error in print(mod): object 'mod' not found
## use random forest to classify iris data
task = makeClassifTask(data = iris, target = "Species")
learner = makeLearner("classif.rpart", minsplit = 7, predict.type = "prob")
mod = train(learner, task, subset = training.set)
#> Error in x[0, , drop = FALSE]: incorrect number of dimensions
print(mod)
#> Error in print(mod): object 'mod' not found