如何通过现有字符和数字列的组合创建新列？

Question

My data is structured as follows:

 Name   Drill Movement Repetition    DV    
1 RUTH 90_Turn   Sprint          1   10   
2 RUTH 90_Turn   Sprint          1   12   
2 RUTH 90_Turn   Sprint          2   12   
2 RUTH 90_Turn   Sprint          2   9    
3 RUTH 90_Turn   Sprint          3   14   
3 RUTH 90_Turn   Sprint          3   12    
4 RUTH 90_Turn   Walk            1   13  
4 RUTH 90_Turn   Walk            1   17   
5 RUTH 90_Turn   Walk            2   11   
5 RUTH 90_Turn   Walk            2   15      

I would like to add in a column Trial that contains a code for each unique combination of Movement and Repetition , such as:

 Name   Drill Movement Repetition    DV     Trial
1 RUTH 90_Turn   Sprint          1   10   D90_Sprint1
2 RUTH 90_Turn   Sprint          1   12   D90_Sprint1
2 RUTH 90_Turn   Sprint          2   12   D90_Sprint2 
2 RUTH 90_Turn   Sprint          2   9    D90_Sprint2 
3 RUTH 90_Turn   Sprint          3   14   D90_Sprint3 
3 RUTH 90_Turn   Sprint          3   12   D90_Sprint3 
4 RUTH 90_Turn   Walk            1   13   D90_Walk1 
4 RUTH 90_Turn   Walk            1   17   D90_Walk1 
5 RUTH 90_Turn   Walk            2   11   D90_Walk2
5 RUTH 90_Turn   Walk            2   15   D90_Walk2

This takes into account the Drill which remains constant, along with Name - the data.frame only consists of Ruth's data for this drill. The DV is measured at least twice per Movement and Repetition .

Is it possible to do this?

My data frame is 10140 obs. so a quick solution would be ideal. Thank you!

Answer 1

We can use paste

df1$Trial <- paste0("D90_", df1$Movement, df1$Repetition)

If '90' comes from the 'Drill' column

df1$Trial <- paste0("D", sub("_.*", "", df1$Drill), "_", df1$Movement, df1$Repetition)

Or with sprintf

sprintf("D%s_%s%d", sub("_.*", "", df1$Drill), df1$Movement, df1$Repetition)
#[1] "D90_Sprint1" "D90_Sprint1" "D90_Sprint2" "D90_Sprint2" "D90_Sprint3" "D90_Sprint3" "D90_Walk1"   "D90_Walk1"   "D90_Walk2"  
#[10] "D90_Walk2" 

Answer 2

Use paste0() :

df$Trial <- paste0(sub("_.*", "", df$Drill),
                   "_",
                   df$Movement,
                   df$Repetition)

The call to sub() extracts the Drill component of the final Trial string.