Convert object to a PredictionClassif.
Usage
as_prediction_classif(x, ...)
# S3 method for PredictionClassif
as_prediction_classif(x, ...)
# S3 method for data.frame
as_prediction_classif(x, ...)Examples
# create a prediction object
task = tsk("penguins")
learner = lrn("classif.rpart", predict_type = "prob")
learner$train(task)
p = learner$predict(task)
# convert to a data.table
tab = as.data.table(p)
# convert back to a Prediction
as_prediction_classif(tab)
#> <PredictionClassif> for 344 observations:
#> row_ids truth response prob.Adelie prob.Chinstrap prob.Gentoo
#> 1 Adelie Adelie 0.96688742 0.03311258 0.00000000
#> 2 Adelie Adelie 0.96688742 0.03311258 0.00000000
#> 3 Adelie Adelie 0.96688742 0.03311258 0.00000000
#> ---
#> 342 Chinstrap Chinstrap 0.06349206 0.92063492 0.01587302
#> 343 Chinstrap Chinstrap 0.28571429 0.71428571 0.00000000
#> 344 Chinstrap Chinstrap 0.06349206 0.92063492 0.01587302
# split data.table into a list of data.tables
tabs = split(tab, tab$truth)
# convert back to list of predictions
preds = lapply(tabs, as_prediction_classif)
# calculate performance in each group
sapply(preds, function(p) p$score())
#> Adelie.classif.ce Chinstrap.classif.ce Gentoo.classif.ce
#> 0.039473684 0.073529412 0.008064516