This is the result container object returned by benchmark().
A BenchmarkResult consists of the data of multiple ResampleResults.
The contents of a BenchmarkResult and ResampleResult are almost identical and the stored ResampleResults can be extracted via the $resample_result(i) method, where i is the index of the performed resample experiment.
This allows us to investigate the extracted ResampleResult and individual resampling iterations, as well as the predictions and models from each fold.
BenchmarkResults can be visualized via mlr3viz's autoplot() function.
For statistical analysis of benchmark results and more advanced plots, see mlr3benchmark.
as.data.table(rr, ..., reassemble_learners = TRUE, convert_predictions = TRUE, predict_sets = "test")
BenchmarkResult -> data.table::data.table()
Returns a tabular view of the internal data.
c(...)
(BenchmarkResult, ...) -> BenchmarkResult
Combines multiple objects convertible to BenchmarkResult into a new BenchmarkResult.
task_type(character(1))
Task type of objects in the BenchmarkResult.
All stored objects (Task, Learner, Prediction) in a single BenchmarkResult are
required to have the same task type, e.g., "classif" or "regr".
This is NA for empty BenchmarkResults.
tasks(data.table::data.table())
Table of included Tasks with three columns:
"task_hash" (character(1)),
"task_id" (character(1)), and
"task" (Task).
learners(data.table::data.table())
Table of included Learners with three columns:
"learner_hash" (character(1)),
"learner_id" (character(1)), and
"learner" (Learner).
Note that it is not feasible to access learned models via this field, as the training task would be ambiguous.
For this reason the returned learner are reset before they are returned.
Instead, select a row from the table returned by $score().
resamplings(data.table::data.table())
Table of included Resamplings with three columns:
"resampling_hash" (character(1)),
"resampling_id" (character(1)), and
"resampling" (Resampling).
resample_results(data.table::data.table())
Returns a table with three columns:
uhash (character()).
resample_result (ResampleResult).
n_resample_results(integer(1))
Returns the total number of stored ResampleResults.
uhashes(character())
Set of (unique) hashes of all included ResampleResults.
data(ResultData)
An object of type ResultData, either extracted from another ResampleResult, another
BenchmarkResult, or manually constructed with as_result_data().
...(ignored).
combine()Fuses a second BenchmarkResult into itself, mutating the BenchmarkResult in-place.
If the second BenchmarkResult bmr is NULL, simply returns self.
Note that you can alternatively use the combine function c() which calls this method internally.
BenchmarkResult$combine(bmr)bmr(BenchmarkResult)
A second BenchmarkResult object.
Returns the object itself, but modified by reference.
You need to explicitly $clone() the object beforehand if you want to keep
the object in its previous state.
marshal()Marshals all stored models.
BenchmarkResult$marshal(...)...(any)
Additional arguments passed to marshal_model().
unmarshal()Unmarshals all stored models.
BenchmarkResult$unmarshal(...)...(any)
Additional arguments passed to unmarshal_model().
score()Returns a table with one row for each resampling iteration, including
all involved objects: Task, Learner, Resampling, iteration number
(integer(1)), and Prediction. If ids is set to TRUE, character
column of extracted ids are added to the table for convenient
filtering: "task_id", "learner_id", and "resampling_id".
Additionally calculates the provided performance measures and binds the performance scores as extra columns. These columns are named using the id of the respective Measure.
BenchmarkResult$score(
measures = NULL,
ids = TRUE,
conditions = FALSE,
predictions = TRUE
)measures(Measure | list of Measure)
Measure(s) to calculate.
ids(logical(1))
Adds object ids ("task_id", "learner_id", "resampling_id") as
extra character columns to the returned table.
conditions(logical(1))
Adds condition messages ("warnings", "errors") as extra
list columns of character vectors to the returned table
predictions(logical(1))
Additionally return prediction objects, one column for each predict_set of all learners combined.
Columns are named "prediction_train", "prediction_test" and "prediction_internal_valid",
if present.
obs_loss()Calculates the observation-wise loss via the loss function set in the
Measure's field obs_loss.
Returns a data.table() with the columns row_ids, truth, response and
one additional numeric column for each measure, named with the respective measure id.
If there is no observation-wise loss function for the measure, the column is filled with
NA values.
Note that some measures such as RMSE, do have an $obs_loss, but they require an
additional transformation after aggregation, in this example taking the square-root.
BenchmarkResult$obs_loss(measures = NULL, predict_sets = "test")measures(Measure | list of Measure)
Measure(s) to calculate.
predict_sets(character())
The predict sets.
aggregate()Returns a result table where resampling iterations are combined into ResampleResults. A column with the aggregated performance score is added for each Measure, named with the id of the respective measure.
The method for aggregation is controlled by the Measure, e.g. micro aggregation, macro aggregation or custom aggregation. Most measures default to macro aggregation.
Note that the aggregated performances just give a quick impression which approaches work well and which approaches are probably underperforming. However, the aggregates do not account for variance and cannot replace a statistical test. See mlr3viz to get a better impression via boxplots or mlr3benchmark for critical difference plots and significance tests.
For convenience, different flags can be set to extract more information from the returned ResampleResult.
BenchmarkResult$aggregate(
measures = NULL,
ids = TRUE,
uhashes = FALSE,
params = FALSE,
conditions = FALSE
)measures(Measure | list of Measure)
Measure(s) to calculate.
ids(logical(1))
Adds object ids ("task_id", "learner_id", "resampling_id") as
extra character columns for convenient subsetting.
uhashes(logical(1))
Adds the uhash values of the ResampleResult as extra character
column "uhash".
params(logical(1))
Adds the hyperparameter values as extra list column "params". You
can unnest them with mlr3misc::unnest().
conditions(logical(1))
Adds the number of resampling iterations with at least one warning as
extra integer column "warnings", and the number of resampling
iterations with errors as extra integer column "errors".
filter()Subsets the benchmark result. If task_ids is not NULL, keeps all
tasks with provided task ids and discards all others tasks.
Same procedure for learner_ids and resampling_ids.
BenchmarkResult$filter(
task_ids = NULL,
task_hashes = NULL,
learner_ids = NULL,
learner_hashes = NULL,
resampling_ids = NULL,
resampling_hashes = NULL
)task_ids(character())
Ids of Tasks to keep.
task_hashes(character())
Hashes of Tasks to keep.
learner_ids(character())
Ids of Learners to keep.
learner_hashes(character())
Hashes of Learners to keep.
resampling_ids(character())
Ids of Resamplings to keep.
resampling_hashes(character())
Hashes of Resamplings to keep.
Returns the object itself, but modified by reference.
You need to explicitly $clone() the object beforehand if you want to keeps
the object in its previous state.
resample_result()Retrieve the i-th ResampleResult, by position or by unique hash uhash.
i and uhash are mutually exclusive.
BenchmarkResult$resample_result(i = NULL, uhash = NULL)i(integer(1))
The iteration value to filter for.
uhash(logical(1))
The ushash value to filter for.
ResampleResult.
discard()Shrinks the BenchmarkResult by discarding parts of the internally stored data. Note that certain operations might stop work, e.g. extracting importance values from learners or calculating measures requiring the task's data.
BenchmarkResult$discard(backends = FALSE, models = FALSE)backends(logical(1))
If TRUE, the DataBackend is removed from all stored Tasks.
models(logical(1))
If TRUE, the stored model is removed from all Learners.
Returns the object itself, but modified by reference.
You need to explicitly $clone() the object beforehand if you want to keeps
the object in its previous state.
clone()The objects of this class are cloneable with this method.
BenchmarkResult$clone(deep = FALSE)deepWhether to make a deep clone.
Chapter in the mlr3book: https://mlr3book.mlr-org.com/chapters/chapter3/evaluation_and_benchmarking.html#sec-benchmarking
Package mlr3viz for some generic visualizations.
mlr3benchmark for post-hoc analysis of benchmark results.
Other benchmark:
benchmark(),
benchmark_grid()
set.seed(123)
learners = list(
lrn("classif.featureless", predict_type = "prob"),
lrn("classif.rpart", predict_type = "prob")
)
design = benchmark_grid(
tasks = list(tsk("sonar"), tsk("penguins")),
learners = learners,
resamplings = rsmp("cv", folds = 3)
)
print(design)
bmr = benchmark(design)
print(bmr)
bmr$tasks
bmr$learners
# first 5 resampling iterations
head(as.data.table(bmr, measures = c("classif.acc", "classif.auc")), 5)
# aggregate results
bmr$aggregate()
# aggregate results with hyperparameters as separate columns
mlr3misc::unnest(bmr$aggregate(params = TRUE), "params")
# extract resample result for classif.rpart
rr = bmr$aggregate()[learner_id == "classif.rpart", resample_result][[1]]
print(rr)
# access the confusion matrix of the first resampling iteration
rr$predictions()[[1]]$confusion
# reduce to subset with task id "sonar"
bmr$filter(task_ids = "sonar")
print(bmr)
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