使用R重塑数据

Question

I am new to R and I have data like below

NAME
----
Balachandra
Sunita
Kali
Jagmeet

I would like to make it as

NAME1       NAME2
-----------------------
Balachandra Balachandra
Balachandra Sunita
Balachandra Kali
Balachandra Jagmeet    
Sunita      Balachandra
Sunita      Sunita
Sunita      Kali
Sunita      Jagmeet    
Kali        Balachandra
Kali        Sunita
Kali        Kali
Kali        Jagmeet    
Jagmeet     Balachandra
Jagmeet     Sunita
Jagmeet     Kali
Jagmeet     Jagmeet    

To have all possible combinations of Names

Any idea how to do that?

Answer 1

We can use expand.grid

expand.grid(NAME1=df1$NAME, NAME = df1$NAME)[2:1]
#      NAME         NAME1
#1  Balachandra Balachandra
#2  Balachandra      Sunita
#3  Balachandra        Kali
#4  Balachandra     Jagmeet
#5       Sunita Balachandra
#6       Sunita      Sunita
#7       Sunita        Kali
#8       Sunita     Jagmeet
#9         Kali Balachandra
#10        Kali      Sunita
#11        Kali        Kali
#12        Kali     Jagmeet
#13     Jagmeet Balachandra
#14     Jagmeet      Sunita
#15     Jagmeet        Kali
#16     Jagmeet     Jagmeet

---

Or use CJ from data.table

library(data.table)
setDT(df1, key = "Name")[CJ(Name, Name)]

data

df1 <- data.frame(NAME = c("Balachandra", "Sunita", "Kali", 
               "Jagmeet"), stringsAsFactors=FALSE)