31 lines
945 B
R
31 lines
945 B
R
setClass('xgb.DMatrix')
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#' Get a new DMatrix containing the specified rows of
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#' orginal xgb.DMatrix object
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#'
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#' Get a new DMatrix containing the specified rows of
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#' orginal xgb.DMatrix object
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#'
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#' @param object Object of class "xgb.DMatrix"
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#' @param idxset a integer vector of indices of rows needed
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#'
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#' @examples
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#' data(iris)
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#' iris[,5] <- as.numeric(iris[,5])
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#' dtrain <- xgb.DMatrix(as.matrix(iris[,1:4]), label=iris[,5])
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#' dsub <- slice(dtrain, 1:3)
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#' @export
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#'
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slice <- function(object, ...){
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UseMethod("slice")
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}
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setMethod("slice", signature = "xgb.DMatrix",
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definition = function(object, idxset) {
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if (class(object) != "xgb.DMatrix") {
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stop("slice: first argument dtrain must be xgb.DMatrix")
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}
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ret <- .Call("XGDMatrixSliceDMatrix_R", object, idxset, PACKAGE = "xgboost")
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return(structure(ret, class = "xgb.DMatrix"))
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})
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