r if 语句 returns 级别数而不是级别文本
r if statement returns number of level rather than the level text
我有一个如下图所示的 table，我正在尝试使用一个简单的 if 语句来 return 国家名称，仅在食物 "Oranges" 的情况下。第 3 列是期望的结果，第 4 列是我在 R 中得到的结果。
在 excel 中，公式为：
=IF(A2="Oranges",B2,"n/a")
我使用以下 r 代码生成 "oranges_country" 变量：
table$oranges_country <- ifelse (Food == "Oranges", Country , "n/a")
[如上图] 代码 return 是 'Country' 级别列表中的级别编号（例如 6），而不是 'Country' 本身（例如 "Spain").我知道这是从哪里来的（摘录中的位置如下），但是这很痛苦，尤其是在使用多个嵌套的 if 语句时。
levels(Country)
[1] "California" "Ecuador" "France" "New Zealand" "Peru" "Spain" "UK"
必须有一个简单的方法来改变这个？？？
按评论要求：dput(table)输出如下：
dput(table)
structure(list(Food = structure(c(1L, 1L, 3L, 1L, 1L, 3L, 3L,
2L, 2L), .Label = c("Apples", "Bananas", "Oranges"), class = "factor"),
Country = structure(c(3L, 7L, 6L, 4L, 7L, 6L, 1L, 5L, 2L), .Label = c("California",
"Ecuador", "France", "New Zealand", "Peru", "Spain", "UK"
), class = "factor"), Desired_If.Outcome = structure(c(2L,
2L, 3L, 2L, 2L, 3L, 1L, 2L, 2L), .Label = c("California",
"n/a", "Spain"), class = "factor"), oranges_country = c("n/a",
"n/a", "6", "n/a", "n/a", "6", "1", "n/a", "n/a"), desiredcolumn = c(NA,
NA, 6L, NA, NA, 6L, 1L, NA, NA)), .Names = c("Food", "Country",
"Desired_If.Outcome", "oranges_country", "desiredcolumn"), row.names = c(NA,
-9L), class = "data.frame")
试试这个（如果你的 table 被称为 table）：
table[table$Food=="Oragnes", ]
尝试 ifelse 循环。首先，将 Table$Country 更改为 character()
table$Country<-as.character(Table$Country)
table$desiredcolumn<-ifelse(table$Food == "Oranges", table$Country, NA)
这是我的版本：
Food<-c("Ap","Ap","Or","Ap","Ap","Or","Or","Ba","Ba")
Country<-c("Fra","UK","Sp","Nz","UK","Sp","Cal","Per","Eq")
Table<-cbind(Food,Country)
Table<-data.frame(Table)
Table$Country<-as.character(Table$Country)
Table$DC<-ifelse(Table$Food=="Or", Table$Country, NA)
Table
Food Country DC
1 Ap Fra <NA>
2 Ap UK <NA>
3 Or Sp Sp
4 Ap Nz <NA>
5 Ap UK <NA>
6 Or Sp Sp
7 Or Cal Cal
8 Ba Per <NA>
9 Ba Eq <NA>
我有一个如下图所示的 table，我正在尝试使用一个简单的 if 语句来 return 国家名称，仅在食物 "Oranges" 的情况下。第 3 列是期望的结果，第 4 列是我在 R 中得到的结果。
在 excel 中，公式为：
=IF(A2="Oranges",B2,"n/a")
我使用以下 r 代码生成 "oranges_country" 变量：
table$oranges_country <- ifelse (Food == "Oranges", Country , "n/a")
[如上图] 代码 return 是 'Country' 级别列表中的级别编号（例如 6），而不是 'Country' 本身（例如 "Spain").我知道这是从哪里来的（摘录中的位置如下），但是这很痛苦，尤其是在使用多个嵌套的 if 语句时。
levels(Country)
[1] "California" "Ecuador" "France" "New Zealand" "Peru" "Spain" "UK"
必须有一个简单的方法来改变这个？？？
按评论要求：dput(table)输出如下：
dput(table)
structure(list(Food = structure(c(1L, 1L, 3L, 1L, 1L, 3L, 3L,
2L, 2L), .Label = c("Apples", "Bananas", "Oranges"), class = "factor"),
Country = structure(c(3L, 7L, 6L, 4L, 7L, 6L, 1L, 5L, 2L), .Label = c("California",
"Ecuador", "France", "New Zealand", "Peru", "Spain", "UK"
), class = "factor"), Desired_If.Outcome = structure(c(2L,
2L, 3L, 2L, 2L, 3L, 1L, 2L, 2L), .Label = c("California",
"n/a", "Spain"), class = "factor"), oranges_country = c("n/a",
"n/a", "6", "n/a", "n/a", "6", "1", "n/a", "n/a"), desiredcolumn = c(NA,
NA, 6L, NA, NA, 6L, 1L, NA, NA)), .Names = c("Food", "Country",
"Desired_If.Outcome", "oranges_country", "desiredcolumn"), row.names = c(NA,
-9L), class = "data.frame")
试试这个（如果你的 table 被称为 table）：
table[table$Food=="Oragnes", ]
尝试 ifelse 循环。首先，将 Table$Country 更改为 character()
table$Country<-as.character(Table$Country)
table$desiredcolumn<-ifelse(table$Food == "Oranges", table$Country, NA)
这是我的版本：
Food<-c("Ap","Ap","Or","Ap","Ap","Or","Or","Ba","Ba")
Country<-c("Fra","UK","Sp","Nz","UK","Sp","Cal","Per","Eq")
Table<-cbind(Food,Country)
Table<-data.frame(Table)
Table$Country<-as.character(Table$Country)
Table$DC<-ifelse(Table$Food=="Or", Table$Country, NA)
Table
Food Country DC
1 Ap Fra <NA>
2 Ap UK <NA>
3 Or Sp Sp
4 Ap Nz <NA>
5 Ap UK <NA>
6 Or Sp Sp
7 Or Cal Cal
8 Ba Per <NA>
9 Ba Eq <NA>