我有一个数据帧，dfregion，如下所示：
dput(dfregion)
structure(list(region = structure(c(1L, 2L, 3L, 3L, 1L), .Label = c("East",
"New England", "Southeast"), class = "factor"), words = structure(c(4L,
2L, 1L, 3L, 5L), .Label = c("buildings, tallahassee", "center, mass, visitors",
"god, instruct, estimated", "seeks, metropolis, convey", "teaching, academic, metropolis"
), class = "factor")), .Names = c("region", "words"), row.names = c(NA,
-5L), class = "data.frame")
region words
1 East seeks, metropolis, convey
3 New England center, mass, visitors
4 Southeast buildings, tallahassee
5 Southeast god, instruct, estimated
6 East teaching, academic, metropolis
我正在努力按区域"融化"或"重塑"此数据帧，然后想将这些单词粘贴在一起。
以下代码是我尝试过的：
dfregionnew<-dcast(dfregion, region ~ words,fun.aggregate= function(x) paste(x) )
dfregionnew<-dcast(dfregion, region ~ words, paste)
dfregionnew <- melt(dfregion,id=c("region"),variable_name="words")
最后，我做到了 - 但是我不确定这是实现我想要的最好方法
dfregionnew<-ddply(dfregion, .(region), mutate, index= paste0('words', 1:length(region)))
dfregionnew<-dcast(dfregionnew, region~ index, value.var ='words')
结果是以正确的方式重塑数据帧，但每个"单词"列都是独立的。随后，我尝试将这些列粘贴在一起，并在这样做时遇到各种错误。
dfregionnew$new<-lapply(dfregionnew[,2:ncol(dfregionnew)], paste, sep=",")
dfregionnew$new<-ldply(apply(dfregionnew, 1, function(x) data.frame(x = paste(x[2:ncol(dfregionnew], sep=",", collapse=NULL))))
dfregionnew$new <- apply( dfregionnew[ , 2:ncol(dfregionnew) ] , 1 , paste , sep = "," )
我能够通过执行以下操作来解决这个问题：
dfregionnew$new <- apply( dfregionnew[ , 2:5] , 1 , paste , collapse = "," )
我想我真正的问题是，是否可以使用 melt 或 dcast 一步完成此操作，而无需在输出后将各个列粘贴在一起。我对提高我的技能非常感兴趣，并希望在 R 中更快/更好的实践。提前感谢！
听起来
您只想将"word"列中的值粘贴在一起，在这种情况下，您应该能够按如下方式使用aggregate：
aggregate(words ~ region, dfregion, paste)
# region words
# 1 East seeks, metropolis, convey, teaching, academic, metropolis
# 2 New England center, mass, visitors
# 3 Southeast buildings, tallahassee, god, instruct, estimated
无需melt或dcast。
如果你确实想使用"reshape2"中的dcast，你可以尝试这样的东西：
dcast(dfregion, region ~ "WORDS", value.var="words",
fun.aggregate=function(x) paste(x, collapse = ", "))
# region WORDS
# 1 East seeks, metropolis, convey, teaching, academic, metropolis
# 2 New England center, mass, visitors
# 3 Southeast buildings, tallahassee, god, instruct, estimated