在数据框上添加一列答案

【问题标题】：Add a column on a dataframe在数据框上添加一列
【发布时间】：2019-01-17 21:00:16
【问题描述】：

如果你能帮忙，我有一个 R 问题。

x <- data.frame("LocationCode" = c("ESC3","RIECAA6","SJHMAU","RIE104","SJH11","SJHAE","RIEAE1","WGH54","RIE205","GSBROB"), "HospitalNumber" = c("701190923R","2905451068","700547389X","AN11295201","1204541612","104010665","800565884R","620063158W","600029720K","1112391223"),"DisciplineName" = c("ESC Biochemistry", "RIE Haematology","SJH Biochemistry","RIE Biochemistry","SJH Biochemistry","WGH Biochemistry","ESC Biochemistry","WGH Biochemistry","SJH Biochemistry","RIE Haematology"))

从上面的数据框中，我确实希望添加一个由所有“HospitalNumber”行组成的新列 (CRN)，其中 9 位数字加上末尾的 1 个字母（例如 701190923R），创建另一列 (TIT)，其余部分不符合第一个条件的行

【问题讨论】：

标签： r

【解决方案1】：

您可以使用代码在 base 中执行此操作

# Identify cases which match 9 digits then one letter
CRMMatch <- grepl("^\\d{9}[[:alpha:]]$", as.character(x$HospitalNumber))
#Create columns from Hospital number among the matches or those that do not match
x$CRN[CRMMatch] <- as.character(x$HospitalNumber)[CRMMatch]
x$TIT[!CRMMatch] <- as.character(x$HospitalNumber)[!CRMMatch]
# clean up by removing the variable created of matches
rm(CRMMatch)

dplyr 版本可能是

library(dplyr)
x <-
  x %>% 
  mutate(CRN = if_else(grepl("^\\d{9}[[:alpha:]]$", as.character(HospitalNumber)),as.character(HospitalNumber), NA_character_),
         TIT = if_else(!grepl("^\\d{9}[[:alpha:]]$", as.character(HospitalNumber)),as.character(HospitalNumber), NA_character_))

【讨论】：

【解决方案2】：

您可以根据说明检测您需要的内容

library(stringr)
str_which(x$HospitalNumber,"[:digit:][:alpha:]")

你会得到：

> str_which(x$HospitalNumber,"[:digit:][:alpha:]")
[1] 1 3 7 8 9

然后你就知道你需要什么职位，你不需要什么

【讨论】：

【解决方案3】：

与 Kerry Jackson 的方法非常相似，但在基础 R 中使用 ifelse。我还从一开始就将您的 x$HospitalNumber 从因子转换为字符，假设这是您真正想要的：

x[2] <- as.character( x[ , 2 ] )
x$CRN <- ifelse( grepl( "^\\d{9}[[:alpha:]]$", x$HospitalNumber) , x$HospitalNumber, "" )
x$TIT <- ifelse( x$CRN != "", "", x$HospitalNumber )

给你

> x
   LocationCode HospitalNumber   DisciplineName        CRN        TIT
1          ESC3     701190923R ESC Biochemistry 701190923R           
2       RIECAA6     2905451068  RIE Haematology            2905451068
3        SJHMAU     700547389X SJH Biochemistry 700547389X           
4        RIE104     AN11295201 RIE Biochemistry            AN11295201
5         SJH11     1204541612 SJH Biochemistry            1204541612
6         SJHAE      104010665 WGH Biochemistry             104010665
7        RIEAE1     800565884R ESC Biochemistry 800565884R           
8         WGH54     620063158W WGH Biochemistry 620063158W           
9        RIE205     600029720K SJH Biochemistry 600029720K           
10       GSBROB     1112391223  RIE Haematology            1112391223

【讨论】：