r - 在 for 循环中对表进行子集化并将其保存为 csv

Question

我对 R 非常陌生，正在尝试使用它来生成大量子集 (>4000)，这是我当前在 JSL 中的脚本无法处理的。如果有人能够指导我如何对下面的表格进行子集化并使用列名称和行信息将其保存为 .csv，我将不胜感激。

set.seed(24)
DT = data.frame(Group=c("A","A","A","A","B","B","B","B","B"),Output1 = rnorm(9),Output2=rnorm(9),Output3=rnorm(9),Step=c("0","0","1","1","1","1","2","2","2"))
DT

我想按 Group,Output[i]、Step 对其进行子集化，并使用特定的命名约定“column_Step_Group.csv”另存为 .csv 文件”。示例如下所示

Output1_0_A.csv

-0.5458808
0.5365853


Output2_0_A.csv
0.002311942
-1.316908124  

Output1_2_B.csv
0.4445853
-0.4664951
-0.8483700

Answer 1

或者在循环中

DT = data.frame(Group=c("A","A","A","A","B","B","B","B","B"),Output1 = rnorm(9),Output2=rnorm(9),Output3=rnorm(9),Step=c("0","0","1","1","1","1","2","2","2"))

for(i in levels(DT$Group)) {
  da <- subset(DT, Group == i)
  write.csv(da, paste("Group_", i, ".csv", sep = ""),  row.names = FALSE, quote = FALSE)
}