dplyr组由于不在Shiny中工作 [英] dplyr group by not working in Shiny
问题描述
我正在使用R闪亮的应用程序,因为我有两个下拉框。第一个下拉列表中填入分类变量,第二个填充数值变量。然后我在分类变量上应用groupby。
这是我的代码。
I am working with R shiny application,in that i have two dropdown boxes. first drop down is populated with categorical variables and second is populated with numerical variables. And then I am applying groupby on categorical variable. Here is my code.
dataset<- dataUpload()
var1 <- as.character(input$variable1)
var2 <- as.character(input$variable2)
v$data <- dataset %>%
group_by(dataset[,var1]) %>%
summarize(Sum=sum(dataset[,var2])) %>%
arrange(desc(Sum))
它给了我下面的输出。
And it gives me following output.
Source: local data frame [7 x 2]
dataset[[var1]] Sum
(fctr) (int)
1 Chicken Biryani 37
2 Chicken Kabab 37
3 Chicken Kadai 37
4 Dal Makhani 37
5 Sai Bhaji and Pulav 37
6 Tava Pulav 37
7 Total Meal 37
这是dish_quantity变量的总和。但我想要这样的东西。
Which is the total sum of dish_quantity variable. But I want something like this.
dish_quant <- df_final %>%
group_by(dish_name) %>%
summarize(Dish_Quantity=sum(dish_quantity)) %>%
arrange(desc(Dish_Quantity))
dish_name Dish_Quantity
(fctr) (int)
1 Chicken Kadai 11
2 Chicken Biryani 9
3 Dal Makhani 6
4 Sai Bhaji and Pulav 3
5 Tava Pulav 3
6 Total Meal 3
7 Chicken Kabab 2
我在哪里做错了?我认为在Shiny中引用数据框的列名是有问题的。
Where am I doing wrong? I think there's a problem with referencing column name of a dataframe while doing it in Shiny.
推荐答案
您遇到 SE / NSE 。 dplyr
会做一些不同的事情,通常你用它的名字来调用它,它会对它进行一些处理。但是,当将它与一个字符变量一起使用时,该魔法将失败,并且您需要回退标准评估。
You are running into problems with SE/NSE. dplyr
does things a little bit differently, normally you call it with the names of columns, which it does some processing on. But, when using it with a character variable, that magic fails, and you need to fall back on standard evaluation.
要修复它,您需要使用标准评估版本的 dplyr
动词(它们以 _
结尾),并在您的函数调用中使用lazyeval。
To fix it, you need to use the standard evaluation versions of the dplyr
verbs (they end in _
), and use lazyeval on your function calls.
下面是使用内置mtcars数据集的代码修正:
Here's a fix for your code, using the builtin mtcars dataset:
library(lazyeval) # so we can use interpret
library(dplyr)
var1 <- "cyl"
var2 <- "mpg"
mtcars %>%
group_by_(var1) %>% #note the _
summarize_(Sum = interp(~sum(x), x = as.name(var2))) %>% #note the _ and the interp call
arrange(desc(Sum))
Source: local data frame [3 x 2]
cyl Sum
(dbl) (dbl)
1 4 293.3
2 8 211.4
3 6 138.2
这篇关于dplyr组由于不在Shiny中工作的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!