R: Handling of column names of 'xgb.DMatrix'

dimnames.xgb.DMatrix {xgboost}

R Documentation

Handling of column names of `xgb.DMatrix`

Description

Only column names are supported for xgb.DMatrix, thus setting of row names would have no effect and returnten row names would be NULL.

Usage

## S3 method for class 'xgb.DMatrix'
dimnames(x)

## S3 replacement method for class 'xgb.DMatrix'
dimnames(x) <- value

Arguments

`x`	object of class `xgb.DMatrix`
`value`	a list of two elements: the first one is ignored and the second one is column names

Details

Generic dimnames methods are used by colnames. Since row names are irrelevant, it is recommended to use colnames directly.

Examples

data(agaricus.train, package='xgboost')
train <- agaricus.train
dtrain <- xgb.DMatrix(train$data, label=train$label)
dimnames(dtrain)
colnames(dtrain)
colnames(dtrain) <- make.names(1:ncol(train$data))
print(dtrain, verbose=TRUE)