Question

我在表的第二列中有一个代码列表，我想提取每个代码的一些元素，然后将它们存储在与每个代码关联的新列中。每个代码由字母后跟一些数字组成。字母是P，F，I，R，C，在所有代码中以相同的顺序重复，但在每个代码中数字的数量是变化的。

例如：考虑以下代码：

P1F2I235R15C145   P1   F2   I23   R15   C145
P24F1I12R124C96   P24  F1   I12   R124  C96

因此，我可以将每个代码拆分为其构成子代码，并将这些组件存储到同一个表中的新列中。感谢

Answer 1

这是一个可能的stringi解决方案

library(stringi)
x <- c("P1F2I235R15C145","P24F1I12R124C96")
res <- stri_split_regex(x,"(?=([A-Za-z]=?))",perl = TRUE,simplify = TRUE,omit_empty = TRUE)
cbind.data.frame(x, res)
#                 x   1  2    3    4    5
# 1 P1F2I235R15C145  P1 F2 I235  R15 C145
# 2 P24F1I12R124C96 P24 F1  I12 R124  C96

Answer 2

试试这个：

#simulate your data frame
df<-data.frame(code=c("P1F2I235R15C145","P24F1I12R124C96"),stringsAsFactors=FALSE)
#split the columns
cbind(df,do.call(rbind,regmatches(df$code,gregexpr("[PFIRC][0-9]+",df$code))))
#             code   1  2    3    4    5
#1 P1F2I235R15C145  P1 F2 I235  R15 C145
#2 P24F1I12R124C96 P24 F1  I12 R124  C96

@AnandaMatho在评论中建议让代码前面的字母消失并相应地命名列。这样的事情：

res<-cbind(df,do.call(rbind,regmatches(df$code,gregexpr("(?<=[PFIRC])[0-9]+",df$code,perl=TRUE))))
names(res)<-c("Code","P","F","I","R","C")
#             Code  P F   I   R   C
#1 P1F2I235R15C145  1 2 235  15 145
#2 P24F1I12R124C96 24 1  12 124  96

Answer 3

data.table解决方案：

library(data.table)
dt<-data.table(code=c("P1F2I235R15C145","P24F1I12R124C96"))
dt[,c("P","F","I","R","C"):=
     lapply(c("P","F","I","R","C"),
            function(x)regmatches(code,regexpr(paste0(x,"[0-9]+"),code)))]

> dt
              code   P  F    I    R    C
1: P1F2I235R15C145  P1 F2 I235  R15 C145
2: P24F1I12R124C96 P24 F1  I12 R124  C96

如果你最终决定放弃前面的字母，那就进行微调：

dt[,c("P","F","I","R","C"):=
     lapply(c("P","F","I","R","C"),
            function(x)regmatches(code,regexpr(paste0("(?<=",x,")[0-9]+"),
                                               code,perl=T)))]
> dt
              code  P F   I   R   C
1: P1F2I235R15C145  1 2 235  15 145
2: P24F1I12R124C96 24 1  12 124  96

或使用devel版本的data.table (v1.9.5+)：

dt[, c("P", "F", "I", "R", "C") := 
      tstrsplit(code, "(?<=.)(?=[[:alpha:]][0-9]+)", perl=TRUE)]
#               code   P  F    I    R    C
# 1: P1F2I235R15C145  P1 F2 I235  R15 C145
# 2: P24F1I12R124C96 P24 F1  I12 R124  C96

如何在R

3 个答案: