在數據框內合併行[有些字段重複]

Question

我有3列。名，審查，在data.frame部分（套）

 name  review    part 
1  abc  this is good  cap 
2  abc  this is not bad cap 
3  abc  this is also good cap 

我想最終的結果看起來是這樣：

 name  review     part 
    1 abc  this is good this  cap 
       is not bad this is 
       also good 

Answer 1

假設你列character類的，你可以這樣做此：

df[sapply(df, duplicated)] <- "" 
> df 
# name   review part 
#1 abc  this is good cap 
#2  this is not bad  
#3  this is also good  

Answer 2

假設 「評論」 列是因子類型的

require(plyr) 
df$review <- as.character(df$review) 

ddply(df, .(name, part), summarize, review = paste(review, collapse = " "))[,c(1,3,2)]