实例 R 语言访问数据帧的项

​x
 
Data_Frame <- data.frame (  Training = c("Strength", "Stamina", "Other"),  Pulse = c(100, 150, 120),  Duration = c(60, 30, 45))​Data_Frame[1]​Data_Frame[["Training"]]​Data_Frame$Training​                    

输出结果

  Training
1 Strength
2  Stamina
3    Other
[1] Strength Stamina  Other   
Levels: Other Stamina Strength
[1] Strength Stamina  Other   
Levels: Other Stamina Strength