在 Reshape2 dcast() 中使用来自 Shiny 的多重输入

Question

参考Using an input from Shiny Widget in Reshape Cast()，我可以通过带有单行变量的闪亮输入创建动态摘要table。

但是，当我想创建多个行层列时，我发现找不到第二个或第三个对象。我试图打印出公式，这似乎是正确的。比如在Shiny中选择了"vs"和"hp"，那么公式就变成了"vs + hp ~ gear"，看起来是正确的。但是出现错误"object 'hp' not found"。

你能帮我解决这个问题吗？谢谢！

UI:

library(shiny)
library(dplyr)
library(reshape2)
library(DT)

ui <- fluidPage(
  headerPanel("Summary Table"),
  sidebarPanel(selectInput("row", "Row variable", names(mtcars), selected = "vs", multiple = T),
               selectInput("col", "Column variable", names(mtcars), selected = "gear")),
  mainPanel(DT::dataTableOutput('table'))
)

服务器：

server <- function(input, output) {

  output$table <- renderDataTable({

    formula <- as.formula(paste(paste(input$row, collapse = "+"), "~", input$col))
    print(formula)

    car0 <- mtcars %>% 
      group_by_(input$row, input$col) %>% 
      summarize(n = n_distinct(cyl)) %>% 
      dcast(formula, value.var = "n")   

    datatable(car0)

  })
}

shinyApp(ui, server)

Answer 1

类似的东西？

library(shiny)
library(dplyr)
library(reshape2)
library(tidyr)
library(DT)
ui <- fluidPage(
  headerPanel("Summary Table"),
  sidebarPanel(selectInput("row", "Row variable", names(mtcars), selected = "vs", multiple = T),
               selectInput("col", "Column variable", names(mtcars), selected = "gear")),
  mainPanel(DT::dataTableOutput('table'))
)

server <- function(input, output) {

  output$table <- renderDataTable({

    car0 <- mtcars %>% 
      select(input$row,input$col,cyl)%>%
      group_by_at(., vars(input$row, input$col))%>%
      summarize(n = n_distinct(cyl))%>%
      tidyr::spread(input$col,n)


    datatable(car0)

  })
}

shinyApp(ui, server)

公式和reshape2

library(shiny)
library(dplyr)
library(reshape2)
library(tidyr)
library(DT)
ui <- fluidPage(
  headerPanel("Summary Table"),
  sidebarPanel(selectInput("row", "Row variable", names(mtcars), selected = "vs", multiple = T),
               selectInput("col", "Column variable", names(mtcars), selected = "gear")),
  mainPanel(DT::dataTableOutput('table'))
)

server <- function(input, output) {

  output$table <- renderDataTable({

    formula <- as.formula(paste(paste(input$row, collapse = "+"), "~", input$col))
    print(formula)

    car0 <- mtcars %>% 
      select(input$row,input$col,cyl)%>%
      group_by_at(., vars(input$row, input$col))%>%
      summarize(n = n_distinct(cyl))%>%
      #tidyr::spread(input$col,n)
      dcast(formula, value.var = "n")  


    datatable(car0)

  })
}

shinyApp(ui, server)

在 Reshape2 dcast() 中使用来自 Shiny 的多重输入

Using an multiple input from Shiny in Reshape2 dcast()

r

reshape2

shiny

dcast