generateFeatureImportanceData(task, method = "permutation.importance",
learner, features = getTaskFeatureNames(task), interaction = FALSE,
measure, contrast = function(x, y) x - y, aggregation = mean, nmc = 50L,
replace = TRUE, local = FALSE)
Task
]
The task.character(1)
]
The method used to compute the feature importance.
The only method available is “permutation.importance”.
Default is “permutation.importance”.Learner
| character(1)
]
The learner.
If you pass a string the learner will be created via makeLearner
.character
]
The features to compute the importance of.
The default is all of the features contained in the Task
.logical(1)
]
Whether to compute the importance of the features
argument jointly.
For method = "permutation.importance"
this entails permuting the values of
all features
together and then contrasting the performance with that of
the performance without the features being permuted.
The default is FALSE
.Measure
]
Performance measure.
Default is the first measure used in the benchmark experiment.function
]
A difference function that takes a numeric vector and returns a numeric vector
of the same length.
The default is element-wise difference between the vectors.function
]
A function which aggregates the differences.
This function must take a numeric vector and return a numeric vector of length 1.
The default is mean
.integer(1)
]
The number of Monte-Carlo iterations to use in computing the feature importance.
If nmc == -1
and method = "permutation.importance"
then all
permutations of the features
are used.
The default is 50.logical(1)
]
Whether or not to sample the feature values with or without replacement.
The default is TRUE
.logical(1)
]
Whether to compute the per-observation importance.
The default is FALSE
.FeatureImportance
]. A named list which contains the computed feature importance and the input arguments. Object members:
data.frame
]
Has columns for each feature or combination of features (colon separated) for which the importance is computed.
A row coresponds to importance of the feature specified in the column for the target.
logical(1)
]
Whether or not the importance of the features
was computed jointly rather than individually.
Measure
]function
]
The function used to compare the performance of predictions.
function
]
The function which is used to aggregate the contrast between the performance of predictions across Monte-Carlo iterations.
logical(1)
]
Whether or not, when method = "permutation.importance"
, the feature values
are sampled with replacement.
integer(1)
]
The number of Monte-Carlo iterations used to compute the feature importance.
When nmc == -1
and method = "permutation.importance"
all permutations are used.
logical(1)
]
Whether observation-specific importance is computed for the features
.
generateCalibrationData
,
generateCritDifferencesData
,
generateFilterValuesData
,
generateFunctionalANOVAData
,
generateLearningCurveData
,
generatePartialDependenceData
,
generateThreshVsPerfData
,
getFilterValues
,
plotFilterValues
lrn = makeLearner("classif.rpart", predict.type = "prob")
fit = train(lrn, iris.task)
imp = generateFeatureImportanceData(iris.task, "permutation.importance",
lrn, "Petal.Width", nmc = 10L, local = TRUE)
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