Question

我想知道如何根据反应输入添加Geomlines。例如，如果我有一个checkboxGroupInput（下面）来选择保险类型，我们如何根据选定的保险类型向ggplot添加行。我还希望能够根据checkboxGroupInput添加多行进行比较。在UI方面，我们可以如下：

                      checkboxGroupInput(inputId = "Model",                                                                               
                              label = h4("What kind of insurance do you use"),                                                                       
                              choices = c("Compound" = "Compound", "Simple" = "Simple", 
                              "Private" = "Private", "Complex" = "Complex"),
                              selected = "Private"
                                                        )

然后在服务器端

Mainplot <- renderPlot({                         
 ggplot(df_norm,aes(x=ages)) +     
 # ADD GEOM_LINE HERE
 )
                        })

我尝试根据输入创建一个对象，然后将其添加到绘图中，但这会在整个过程中产生错误。例如，

Line <- if ((input$Model == "Private") {"geom_line(aes(y=Private_line), size=0.5) +"} else { "  "})

然后在情节中

Mainplot <- renderPlot({                         
 ggplot(df_norm,aes(x=ages)) +     
 Line()
 )
                        })

然而，这会产生错误“ggplot不知道如何处理RHS”。

感谢您提供的任何帮助， Conal

Answer 1

您可以使用select中的dplyr来选择要显示的数据框列，gather tidyr个数据包，以便在数据框中收集它们并将它们分开按颜色：

library(ggplot2)
library(tidyr)
library(dplyr)

ui <- fluidPage(
  sidebarLayout(
    sidebarPanel(
      checkboxGroupInput(inputId = "line",                                                                               
                         label = h4("What would you like to plot?"),                                                                       
                         choices = names(mtcars))

    ),
    mainPanel(
      plotOutput("plot")
    )
  )
)

server <- function(input, output) {
  output$plot <- renderPlot({             
    validate(need(!is.null(input$line), 'Please tick a box to show a plot.'))
    # 1. mpg is our fixed x-value
    # 2. select variables of mtcars you need using select()
    # 3. gather all selected variables in two columns: variable/value (but not mpg since that is the x value)
    data <- gather(select(mtcars, "mpg", input$line), variable, value, -mpg)

    # the plot, coloured by variable
    ggplot(data, aes(x=mpg, y = value, colour = variable)) + geom_point()
  })
}

shinyApp(ui, server)

带有反应性Geom线的ggplot2

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