nchar() in R

We will redefine a new train-test split of the data. Use the sample function generate a vector index2 of random record numbers spanning 75% of the rows of dataframe gdat. Paste your R code in BOX 1 [Format:a42] '{r} 2 Generate a training dataset called trainglassnb by taking the records in rows index1 in dataframe gdat Paste your R code in BOX 2 [Format:a27] {r} 3 Generate a testing dataset called testglassnb by taking the complement of the records in rows index1 in dataframe gdat Paste your R code in BOX 3 [Format:a27] '{r}