Boxuan - 6 months ago 23

R Question

I have a data frame as follow:

`+-----+-------+`

| V1 | V2 |

+-----+-------+

| 1 | a,b,c |

| 2 | a,c |

| 3 | b,d |

| 4 | e,f |

| . | . |

+-----+-------+

Each of the alphabet is a character separated by comma. I would like to split V2 on each comma and insert the split strings as new rows. For instance, the desired output will be:

`+----+----+`

| V1 | V2 |

+----+----+

| 1 | a |

| 1 | b |

| 1 | c |

| 2 | a |

| 2 | c |

| 3 | b |

| 3 | d |

| 4 | e |

| 4 | f |

+----+----+

I am trying to use

`strsplit()`

Answer

Here is another way of doing it..

```
df <- read.table(textConnection("1|a,b,c\n2|a,c\n3|b,d\n4|e,f"), header = F, sep = "|", stringsAsFactors = F)
df
## V1 V2
## 1 1 a,b,c
## 2 2 a,c
## 3 3 b,d
## 4 4 e,f
s <- strsplit(df$V2, split = ",")
data.frame(V1 = rep(df$V1, sapply(s, length)), V2 = unlist(s))
## V1 V2
## 1 1 a
## 2 1 b
## 3 1 c
## 4 2 a
## 5 2 c
## 6 3 b
## 7 3 d
## 8 4 e
## 9 4 f
```