Function xgboost_sys::XGDMatrixSliceDMatrix

pub unsafe extern "C" fn XGDMatrixSliceDMatrix(
    handle: DMatrixHandle,
    idxset: *const c_int,
    len: bst_ulong,
    out: *mut DMatrixHandle
) -> c_int

\brief create a new dmatrix from sliced content of existing matrix \param handle instance of data matrix to be sliced \param idxset index set \param len length of index set \param out a sliced new matrix \return 0 when success, -1 when failure happens