r - 无法将 xgb.DMatrix 传递给插入符

Question

我正在尝试使用插入符号库调整 xgboost 的超参数来解决分类问题，由于我的数据集中有很多因素，并且 xgboost 喜欢将数据作为数字，所以我使用特征哈希创建了一个虚拟行，但是当我得到运行插入符列车，我收到错误

#Using Feature hashing to convert all the factor variables to dummies
objTrain_hashed = hashed.model.matrix(~., data=train1[,-27], hash.size=2^15, transpose=FALSE)
#created a dense matrix which is normally accepted by xgboost method in R
#Hoping I could pass it caret as well
dmodel  <- xgb.DMatrix(objTrain_hashed[, ], label = train1$Walc)

xgb_grid_1 = expand.grid(
  nrounds = 500, 
  max_depth = c(5, 10, 15), 
  eta = c(0.01, 0.001, 0.0001), 
  gamma = c(1, 2, 3), 
  colsample_bytree = c(0.4, 0.7, 1.0), 
  min_child_weight = c(0.5, 1, 1.5)
)


xgb_trcontrol_1 = trainControl(
  method = "cv",
  number = 3,
  verboseIter = TRUE,
  returnData = FALSE,
  returnResamp = "all",                                                        # save losses across all models
  classProbs = TRUE,                                                           # set to TRUE for AUC to be computed
  summaryFunction = twoClassSummary,
  allowParallel = TRUE
)

xgb_train1 <- train(Walc ~.,dmodel,method = 'xgbTree',trControl = xgb_trcontrol_1,
                    metric = 'accuracy',tunegrid = xgb_grid_1)

我收到以下错误

Error in as.data.frame.default(data) : 
  cannot coerce class ""xgb.DMatrix"" to a data.frame

关于我如何继续的任何建议？

Answer 1

这是因为您将 dmodel 输入到代码的最后部分。尝试输入 objTrain_hashed，它是一个矩阵，而不是 xgb.DMatrix