分割數據框中的列？

我有我的數據幀鬧分裂列：分割數據框中的列？

2010 census 2014 land area   city 
8175133  302.6 sq mi 783.8 km2  New york 
3792621  468.7 sq mi 1213.9 km2 Los Angeles 
2695598  227.7 sq mi 589.6 km2  Chicago

我想：

2010 census area sq/mi  area sq/km   city 
8175133  302.6   783.8    New york 
3792621  468.7   1213.9    Los Angeles 
2695598  227.7   589.6    Chicago

來源

2017-06-30 Clinton Woods

請認真閱讀[如何在R中創建一個很好的重現示例]（https://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example）。 – Masoud

*「我有麻煩」* ...有什麼問題？如果您顯示您嘗試過的代碼以及您收到的錯誤或輸出，這將有所幫助。（請閱讀Masoud提供的鏈接，它非常有幫助，並且會提高更快得到答案的可能性。） – r2evans

另一個基礎R：'with（df，cbind（df，do.call（rbind，regmatches（land.area ，gregexpr（「[0-9] + \\。* [0-9] +」，land.area）））））' – user20650

這是一個tidyr解決方案。

library(tidyr) 

df <- data.frame(census = c(8175133, 3792621, 2695598), 
       land.area = c("302.6 sq mi 783.8 km2", "468.7 sq mi 1213.9 km2", "227.7 sq mi 589.6 km2"), 
       city = c("New york","Los Angeles","Chicago"), stringsAsFactors = FALSE) 

df$land.area <- sapply(df$land.area, sub, pattern = " km2", replacement = "") 

df <- df %>% separate(col = land.area, into = c("area sq/mi", "area sq/km"), sep = " sq mi ")

來源

2017-06-30 20:23:22

您可以使用stringr::str_split_fixed：

library(stringr) 
splitted <- str_split_fixed(dt$X2014.land.area, " sq mi ", 2) 

splitted[,2] <- gsub(" km2", "", as.character(splitted[,2])) 

colnames(splitted) <- c("area sq. mi", "area sq km") 

splitted <- data.frame(splitted) 


dt.2 <- cbind(dt[,c(1,3)], splitted) 

dt.2 

# X2010.census  city area.sq..mi area.sq.km 
# 1  8175133 New york  302.6  783.8 
# 2  3792621 Los Angeles  468.7  1213.9 
# 3  2695598  Chicago  227.7  589.6

數據

structure(list(X2010.census = c(8175133L, 3792621L, 2695598L), 
    X2014.land.area = c("302.6 sq mi 783.8 km2", "468.7 sq mi 1213.9 km2", 
    "227.7 sq mi 589.6 km2"), city = c("New york", "Los Angeles", 
    "Chicago")), .Names = c("X2010.census", "X2014.land.area", 
    "city"), row.names = c(NA, -3L), class = "data.frame") -> dt

來源

2017-06-30 20:18:17 Masoud

下面是使用sub

dt$Area_SqMi = sub("\\s*sq\\s*mi.*", "", dt$X2014.land.area) 
dt$Area_km2 = sub(".*mi\\s+(\\S+)\\s+km2.*", "\\1", dt$X2014.land.area) 

dt 
    X2010.census  X2014.land.area  city Area_SqMi Area_km2 
1  8175133 302.6 sq mi 783.8 km2 New york  302.6 783.8 
2  3792621 468.7 sq mi 1213.9 km2 Los Angeles  468.7 1213.9 
3  2695598 227.7 sq mi 589.6 km2  Chicago  227.7 589.6

當然，一個基礎R解決方案，如果你想擺脫原始列的，你可以添加dt = dt[,-2]

來源

2017-06-30 20:27:03 G5W

使用data.table和tstrsplit功能從該包裝：

dat <- fread("2010 census, 2014 land area, city 
       8175133, 302.6 sq mi 783.8 km2, New york 
       3792621, 468.7 sq mi 1213.9 km2, Los Angeles 
       2695598, 227.7 sq mi 589.6 km2, Chicago") 
dat[, c("area sq/mi", "area sq/km") := tstrsplit(`2014 land area`, " ", keep = c(1,4))] 
dat[, .(`2010 census`, `area sq/mi`, `area sq/km`, city)] 

# 2010 census area sq/mi area sq/km  city 
# 1:  8175133  302.6  783.8 New york 
# 2:  3792621  468.7  1213.9 Los Angeles 
# 3:  2695598  227.7  589.6  Chicago

來源

2017-06-30 22:25:29

分割數據框中的列？

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