Get a new DMatrix containing the specified rows of original xgb.DMatrix object

Get a new DMatrix containing the specified rows of original xgb.DMatrix object

slice(object, ...)

# S3 method for xgb.DMatrix
slice(object, idxset, ...)

# S3 method for xgb.DMatrix
[(object, idxset, colset = NULL)

Arguments

object	Object of class "xgb.DMatrix"
...	other parameters (currently not used)
idxset	a integer vector of indices of rows needed
colset	currently not used (columns subsetting is not available)

Examples

data(agaricus.train, package='xgboost')
train <- agaricus.train
dtrain <- xgb.DMatrix(train$data, label=train$label)

dsub <- slice(dtrain, 1:42)
labels1 <- getinfo(dsub, 'label')
dsub <- dtrain[1:42, ]
labels2 <- getinfo(dsub, 'label')
all.equal(labels1, labels2)
#> [1] TRUE