selectInput 不返回 ALL 并将因子转换为闪亮的数字

Question

在Shiny中，我希望在使用

All

时能够选择

selectInput

。

但是，在下面的shiny应用程序中，当我使用

selectInput

作为列

Species

并为

All

指定选项

choices

时，shiny将列转换为数字（而不是因子）。

library(shiny)
library(palmerpenguins)

# Load the palmerpenguins dataset
data("penguins")

# Define UI
ui <- fluidPage(
  titlePanel("Penguin Species Selector"),
  
  sidebarLayout(
    sidebarPanel(
      selectInput("species", "Select Species:",
                  choices = c("All", unique(penguins$species))),
      hr(),
      helpText("Select a species to view its data.")
    ),
    
    mainPanel(
      tableOutput("penguin_table")
    )
  )
)

# Define server logic
server <- function(input, output) {
  output$penguin_table <- renderTable({
    if (input$species == "All") {
      return(penguins)
    } else {
      return(subset(penguins, species == input$species))
    }
  })
}

# Run the application
shinyApp(ui = ui, server = server)

当我删除

All

并使用这个

choices = unique(penguins$species)

（见下文）时，闪亮的应用程序会将列显示为一个因素，但现在我无法选择

All

library(shiny)
library(palmerpenguins)

# Load the palmerpenguins dataset
data("penguins")

# Define UI
ui <- fluidPage(
  titlePanel("Penguin Species Selector"),
  
  sidebarLayout(
    sidebarPanel(
      selectInput("species", "Select Species:",
                  choices = unique(penguins$species)),
      hr(),
      helpText("Select a species to view its data.")
    ),
    
    mainPanel(
      tableOutput("penguin_table")
    )
  )
)


# Define server logic
server <- function(input, output) {
  output$penguin_table <- renderTable({
    if (input$species == "All") {
      return(penguins)
    } else {
      return(subset(penguins, species == input$species))
    }
  })
}

# Run the application
shinyApp(ui = ui, server = server)

Answer 1

这是因为

factor

在内部存储为数字。一个简单的解决方法是将物种转变为角色。

choices = c("All", unique(as.character(penguins$species)))

完整代码-

library(shiny)
library(palmerpenguins)

# Load the palmerpenguins dataset
data("penguins")

# Define UI
ui <- fluidPage(
  titlePanel("Penguin Species Selector"),
  
  sidebarLayout(
    sidebarPanel(
      selectInput("species", "Select Species:",
                  choices = c("All", unique(as.character(penguins$species)))),
      hr(),
      helpText("Select a species to view its data.")
    ),
    
    mainPanel(
      tableOutput("penguin_table")
    )
  )
)

# Define server logic
server <- function(input, output) {
  output$penguin_table <- renderTable({
    if (input$species == "All") {
      return(penguins)
    } else {
      return(subset(penguins, species == input$species))
    }
  })
}

# Run the application
shinyApp(ui = ui, server = server)