在R中合并2个具有相同但不同案例列的数据框答案

【问题标题】：merge 2 dataframe with same but different case column in R在R中合并2个具有相同但不同案例列的数据框
【发布时间】：2017-07-14 11:06:58
【问题描述】：

我有两个数据框，但问题是合并“按”列在不同情况下具有值。

sn1capx1e0001 与 SN1CAPX1E0001。

authors <- data.frame(
surname = I(c("Tukey", "Venables", "Tierney", "Ripley", "McNeil")),
nationality = c("US", "Australia", "US", "UK", "Australia"),
deceased = c("yes", rep("no", 4)))

books <- data.frame(
name = I(c("tukey", "venables", "tierney",
           "tipley", "ripley", "McNeil", "R Core")),
title = c("Exploratory Data Analysis",
          "Modern Applied Statistics ...",
          "LISP-STAT",
          "Spatial Statistics", "Stochastic Simulation",
          "Interactive Data Analysis",
          "An Introduction to R"),
other.author = c(NA, "Ripley", NA, NA, NA, NA,
                 "Venables & Smith"))
m1 <- merge(authors, books, by.x = "surname", by.y = "name")

给予

姓国籍已故头衔其他作者

McNeil 澳大利亚没有交互式数据分析 NA

所以我想通过不区分大小写来合并它们。我无法使用合并或加入。

我看到我们可以使用正则表达式通过循环来匹配值。

【问题讨论】：

标签： r

【解决方案1】：

我发现这很简单

使用 "toupper()" 隐藏两者

books$name<-toupper(books$name)

简单....

【讨论】：

【解决方案2】：

为什么不将它们转换成相同的形式？

library(stringr)

authors <- data.frame(
  surname = I(c("Tukey", "Venables", "Tierney", "Ripley", "McNeil")),
  nationality = c("US", "Australia", "US", "UK", "Australia"),
  deceased = c("yes", rep("no", 4)))

books <- data.frame(
  name = I(c("tukey", "venables", "tierney",
             "tipley", "ripley", "McNeil", "R Core")),
  title = c("Exploratory Data Analysis",
            "Modern Applied Statistics ...",
            "LISP-STAT",
            "Spatial Statistics", "Stochastic Simulation",
            "Interactive Data Analysis",
            "An Introduction to R"),
  other.author = c(NA, "Ripley", NA, NA, NA, NA,
                   "Venables & Smith"))

authors$surname <- str_to_title(authors$surname)
books$name <- str_to_title(books$name)

m1 <- merge(authors, books, by.x = "surname", by.y = "name")

给予

   surname nationality deceased                         title other.author
1   Mcneil   Australia       no     Interactive Data Analysis         <NA>
2   Ripley          UK       no         Stochastic Simulation         <NA>
3  Tierney          US       no                     LISP-STAT         <NA>
4    Tukey          US      yes     Exploratory Data Analysis         <NA>
5 Venables   Australia       no Modern Applied Statistics ...       Ripley

【讨论】：