r - R中的多数投票函数和网格调整

Question

如何在 R 中创建一个产生多数票的函数？我想对 XGBoost 模型的一些参数进行网格搜索。我的目标是通过网格搜索中每个分类器组合的多数投票来选择最佳 XGBoost 模型。

library(datasets)
library(xgboost)
library(caret)
library(dplyr)
library(caTools)

data(iris)
iris$ID<- 1:nrow(iris)

  
for(i in iris$ID) {
  mytrain <- iris %>%
    filter(ID != i) %>%
    select(!ID) 
  mytest <- iris %>%
    filter(ID == i) %>%
    select(!ID) 
}

ctrl <- trainControl(method = "LOOCV",
                     number = 10, 
                     classProbs = TRUE,
                     #summaryFunction = MajVot, <- should I insert here the Maj voting function?
                     allowParallel=TRUE,
                     verboseIter = F,
                     savePredictions=T)

tune_grid <- expand.grid(nrounds=c(100), 
                         max_depth = c(1:10),
                         eta = c(0.01,0.05),
                         gamma = c(0.01,0.5),
                         colsample_bytree = c(0.75),
                         subsample = c(0.50),
                         min_child_weight = c(0,10))

m <- caret::train(Species ~ .,
                  data = mytrain,
                  method = "xgbTree",
                  metric="ROC",
                  tuneGrid = tune_grid,
                  verbose = FALSE,
                  trControl = ctrl)