Pass rows of a data frame as parameters to a function while keeping other arguments constant

Question

Following up on Pass rows of a data frame as arguments to a function in R with column names specifying the arguments:

I want to train the following model with differ

Answer 1

You can use mapply():

models_list <- mapply(function(x,y,z) xgboost(data = train,
                                              label = df$y,
                                              # parameters
                                              nrounds = x,
                                              subsample = y,
                                              colsample_bytree = z),
                      param$nrounds, param$subsample, param$colsample_bytree, SIMPLIFY = FALSE)

It will give you a list of all your models:

>models_list[[1]]
##### xgb.Booster
raw: 25.2 Kb 
call:
  xgb.train(params = params, data = dtrain, nrounds = nrounds, 
    watchlist = watchlist, verbose = verbose, print_every_n = print_every_n, 
    early_stopping_rounds = early_stopping_rounds, maximize = maximize, 
    save_period = save_period, save_name = save_name, xgb_model = xgb_model, 
    callbacks = callbacks, subsample = ..1, colsample_bytree = ..2)
params (as set within xgb.train):
  subsample = "0.5", colsample_bytree = "0.8", silent = "1"
xgb.attributes:
  niter
callbacks:
  cb.print.evaluation(period = print_every_n)
  cb.evaluation.log()
  cb.save.model(save_period = save_period, save_name = save_name)
niter: 10
evaluation_log:
    iter train_rmse
       1   0.487354
       2   0.473657
---                
       9   0.419176
      10   0.412587