2017-07-26 76 views
1

我有一个数据框,包含组列和几个数字列。另外,我有一个变量,它存储了我需要排名观察的列名。之所以这样说,是我的数据帧基于动态变量名称的组的排名观察

> x = "myValue1" 
> set.seed(123) 
> df = data.frame(myValue1 = rnorm(9, mean = 10), 
        myValue2 = rnorm(9, mean = 2), 
        myGroup = rep(c("a","b","c"), each = 3), 
        myEntity = paste0("entity",1:9)) 
> df 
    myValue1 myValue2 myGroup myEntity 
1 9.439524 1.55433803  a entity1 
2 9.769823 3.22408180  a entity2 
3 11.558708 2.35981383  a entity3 
4 10.070508 2.40077145  b entity4 
5 10.129288 2.11068272  b entity5 
6 11.715065 1.44415887  b entity6 
7 10.460916 3.78691314  c entity7 
8 8.734939 2.49785048  c entity8 
9 9.313147 0.03338284  c entity9 

我要的是每个组中,从x返回的每个观察使用列等级(在这种情况下,它是myValue1)。所以,我想返回以下数据帧

> library(dplyr) 
> df = data.frame(df %>% 
        group_by(myGroup) %>% 
        mutate(myRank = order(myValue1,myEntity))) 
> df 
     myValue1 myValue2 myGroup myEntity myRank 
    1 9.439524 1.55433803  a entity1  1 
    2 9.769823 3.22408180  a entity2  2 
    3 11.558708 2.35981383  a entity3  3 
    4 10.070508 2.40077145  b entity4  1 
    5 10.129288 2.11068272  b entity5  2 
    6 11.715065 1.44415887  b entity6  3 
    7 10.460916 3.78691314  c entity7  2 
    8 8.734939 2.49785048  c entity8  3 
    9 9.313147 0.03338284  c entity9  1 

这很简单,因为我输入了列名。我的问题是如何使用变量x而不是在此公式中输入列名称。 这是我尝试没有成功(它们都返回错误)

> df = data.frame(df %>% group_by(myGroup) %>% mutate(myRank = order(x,myEntity))) 
> df = data.frame(df %>% group_by(myGroup) %>% mutate(myRank = order(as.name(x),myEntity))) 
> df = data.frame(df %>% group_by(myGroup) %>% mutate(myRank = order(noquote(x),myEntity))) 
> library(plyr) 
> df = ddply(df,.(myGroup),transform,Order = rank(as.name(x))) 

我也看了看这里的问题similar question,但不能使之成为我的方案工作。

+1

你的方法用'as.name() ''''''''''''''''''''''''''''''如果你从'rlang'周围包裹unquote运算符'UQ()',将会起作用 –

回答

1

您可以使用.data代词指变量与字符串:

x <- "myValue1" 

df %>% 
    group_by(myGroup) %>% 
    mutate(myRank = order(.data[[x]], myEntity)) 

或者使用sym()rlang与所享有运营商UQ()

df %>% 
    group_by(myGroup) %>% 
    mutate(myRank = order(UQ(rlang::sym(x)), myEntity)) 
+1

这太好了。谢谢Steven。 – BICube