R:拆分字符列并创建两个新的
R: Split character column and create two new ones
R 用户
我有一个类似这样的数据框:
a <- c("John, 3 years")
b <- c("Mokobe, 11 years")
c <- c("Ivan")
df <- rbind(a,b,c)
df
[,1]
a "John, 3 years"
b "Mokobe, 11 years"
c "Ivan"
逗号后的列拆分应该用哪个函数得到:
df
[,1] [,2]
John 3 years
Mokobe 11 years
Ivan NA
我们可以通过分隔符 ,
做一个 strsplit
然后 rbind
在最后用 NA
填充后的 list
元素使 length
每个 list
元素相同
lst <- strsplit(df[,1], ", ")
do.call(rbind, lapply(lst, `length<-`, max(lengths(lst))))
# [,1] [,2]
#a "John" "3 years"
#b "Mokobe" "11 years"
#c "Ivan" NA
使用 tidyr 库:
library(tidyr)
df <- as.data.frame(rbind(a,b,c), stringsAsFactors=F)
separate(df, V1, c("name", "age"),sep = ",")
直接用read.csv
和fill=TRUE
和header=FALSE
读取数据即可。您可以通过 as.matrix()
决定将其更改为矩阵
read.csv(text=df,fill=T,header=F,na.strings = "")
V1 V2
1 John 3 years
2 Mokobe 11 years
3 Ivan <NA>
求矩阵。虽然没必要
as.matrix(read.csv(text=df,fill=1,h=0,na.strings = ""))
V1 V2
[1,] "John" " 3 years"
[2,] "Mokobe" " 11 years"
[3,] "Ivan" NA
# This should work
library(stringr)
a <- c("John, 3 years")
b <- c("Mokobe, 11 years")
c <- c("Ivan")
df<- rbind(a,b,c)
df<- str_split_fixed(df, ",", 2)
R 用户
我有一个类似这样的数据框:
a <- c("John, 3 years")
b <- c("Mokobe, 11 years")
c <- c("Ivan")
df <- rbind(a,b,c)
df
[,1]
a "John, 3 years"
b "Mokobe, 11 years"
c "Ivan"
逗号后的列拆分应该用哪个函数得到:
df
[,1] [,2]
John 3 years
Mokobe 11 years
Ivan NA
我们可以通过分隔符 ,
做一个 strsplit
然后 rbind
在最后用 NA
填充后的 list
元素使 length
每个 list
元素相同
lst <- strsplit(df[,1], ", ")
do.call(rbind, lapply(lst, `length<-`, max(lengths(lst))))
# [,1] [,2]
#a "John" "3 years"
#b "Mokobe" "11 years"
#c "Ivan" NA
使用 tidyr 库:
library(tidyr)
df <- as.data.frame(rbind(a,b,c), stringsAsFactors=F)
separate(df, V1, c("name", "age"),sep = ",")
直接用read.csv
和fill=TRUE
和header=FALSE
读取数据即可。您可以通过 as.matrix()
read.csv(text=df,fill=T,header=F,na.strings = "")
V1 V2
1 John 3 years
2 Mokobe 11 years
3 Ivan <NA>
求矩阵。虽然没必要
as.matrix(read.csv(text=df,fill=1,h=0,na.strings = ""))
V1 V2
[1,] "John" " 3 years"
[2,] "Mokobe" " 11 years"
[3,] "Ivan" NA
# This should work
library(stringr)
a <- c("John, 3 years")
b <- c("Mokobe, 11 years")
c <- c("Ivan")
df<- rbind(a,b,c)
df<- str_split_fixed(df, ",", 2)