好的,使用從here的想法改進上述答案。將重複和非重複的列保存到數據框中。檢查非重複項是否與任何重複項匹配,如果是,則連接它們的列名。所以,如果你有兩個以上的重複列,現在就可以工作。
編輯:更改summary
到digest
。這有助於角色數據。
df <- structure(list(test1 = c(1, 2, 3, 4, 5, 6), test2 = c(1, 2, 4,
4, 5, 6), test3 = c(0, 2, 4, 4, 5, 6), test4 = c(1, 2, 3, 4,
5, 6)), .Names = c("test1", "test2", "test3", "test4"), row.names = c(NA,
-6L), class = "data.frame")
library(digest)
nondups <- df[!duplicated(lapply(df, digest))]
dups <- df[duplicated(lapply(df, digest))]
for(i in 1:ncol(nondups)){
for(j in 1:ncol(dups)){
if(FALSE %in% paste0(nondups[,i] == dups[,j])) NULL
else names(nondups)[i] <- paste(names(nondups[i]), names(dups[j]), sep = "+")
}
}
nondups
例2中,作爲函數。
編輯:更改summary
到digest
並返回非重複和重複的數據幀。
age <- 18:29
height <- c(76.1,77,78.1,78.2,78.8,79.7,79.9,81.1,81.2,81.8,82.8,83.5)
gender <- c("M","F","M","M","F","F","M","M","F","M","F","M")
testframe <- data.frame(age=age,height=height,height2=height,gender=gender,gender2=gender, gender3 = gender)
dupcols <- function(df = testframe){
nondups <- df[!duplicated(lapply(df, digest))]
dups <- df[duplicated(lapply(df, digest))]
for(i in 1:ncol(nondups)){
for(j in 1:ncol(dups)){
if(FALSE %in% paste0(nondups[,i] == dups[,j])) NULL
else names(nondups)[i] <- paste(names(nondups[i]), names(dups[j]), sep = "+")
}
}
return(list(df1 = nondups, df2 = dups))
}
dupcols(df = testframe)
Editted:這部分是新的。
例3:在一個大的數據幀
#Creating a 1500 column by 15000 row data frame
dat <- do.call(data.frame, replicate(1500, rep(FALSE, 15000), simplify=FALSE))
names(dat) <- 1:1500
#Fill the data frame with LETTERS across the rows
#This part may take a while. Took my PC about 23 minutes.
start <- Sys.time()
fill <- rep(LETTERS, times = ceiling((15000*1500)/26))
j <- 0
for(i in 1:nrow(dat)){
dat[i,] <- fill[(1+j):(1500+j)]
j <- j + 1500
}
difftime(Sys.time(), start, "mins")
#Run the function on the created data set
#This took about 4 minutes to complete on my PC.
start <- Sys.time()
result <- dupcols(df = dat)
difftime(Sys.time(), start, "mins")
names(result$df1)
ncol(result$df1)
ncol(result$df2)
我們必須假設你用Google搜索「R刪除重複列」。請說明爲什麼前幾個命中沒有幫助。否則,這個問題將作爲重複被關閉。 – Henrik
是的,我有。請查看結果表中的列名。我不僅想刪除重複的列。我也想在刪除重複項後合併重複列的列名。我可以手動完成我發佈的簡單表格,但我想在大型數據集上使用它。 – arielle
您是否事先知道哪些列是重複的?或者你想自動確定 – MichaelChirico