如何基于selectInput的值切换Shiny应用中的数据集？

你的问题出在缓存依赖设置不全：selected_data和pitcher_table的缓存只绑定了input$pitcher，当切换数据集（input$dataset）时，缓存不会自动更新，导致始终显示之前选中投手的2024年数据。

具体修复步骤： #

1. 补全缓存依赖项：在selected_data和renderReactable的bindCache中加入input$dataset，确保切换数据集时触发数据更新。
2. 优化投手选择框联动：切换数据集时重置投手选择，避免选中的投手在新数据集中不存在，导致显示空表。

修改后的完整代码： #

library(shiny)
library(ggplot2)
library(dplyr)
library(glue)
library(reactable)
final_2023_with_percentile <- structure(list(player_name = c("Abbott, Andrew", "Abbott, Andrew", 
                                                             "Abbott, Andrew", "Abbott, Andrew", "Abreu, Bryan"), api_pitch_type = c("CH", 
                                                                                                                                     "CU", "FF", "ST", "FF"), `Horizontal Break` = c(14.5784810126582, 
                                                                                                                                                                                     -8.75646017699115, 7.72310797174571, -11.787027027027, -7.55102362204724
                                                                                                                                     ), `Induced Vertical Break` = c(10.763164556962, -3.3975221238938, 
                                                                                                                                                                     16.3276286579213, 5.79423423423423, 16.278188976378), `Pitch Velocity` = c(86.6278481012658, 
                                                                                                                                                                                                                                                80.8719764011799, 92.7466195761857, 82.9141141141141, 97.5663385826772
                                                                                                                                                                     ), pitch_usage = c(15.959595959596, 17.1212121212121, 50.050505050505, 
                                                                                                                                                                                        16.8181818181818, 41.1336032388664), avg_arm_angle = c(44.6095238095238, 
                                                                                                                                                                                                                                               49.552380952381, 45.7190476190476, 43.8, 40.1347222222222), pitch_group = c("Offspeed", 
                                                                                                                                                                                                                                                                                                                           "Breaking", "Fastball", "Breaking", "Fastball"), year = c(2023, 
                                                                                                                                                                                                                                                                                                                                                                                     2023, 2023, 2023, 2023), expected_arm_angle = c(45.3313248212314, 
                                                                                                                                                                                                                                                                                                                                                                                                                                     48.0091346481901, 43.3291879571372, 45.1739731517787, 42.3795663314202
                                                                                                                                                                                                                                                                                                                                                                                     ), difference = c(-0.721801011707591, 1.54324630419084, 2.38985966191041, 
                                                                                                                                                                                                                                                                                                                                                                                                       -1.3739731517787, -2.24484410919793), difference_percentile = c(11, 
                                                                                                                                                                                                                                                                                                                                                                                                                                                                       36, 61, 32, 59)), row.names = c(NA, -5L), class = c("tbl_df", 
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           "tbl", "data.frame"))
final_2024_with_percentile <- structure(list(player_name = c("Abbott, Andrew", "Abbott, Andrew", 
                                                             "Abbott, Andrew", "Abbott, Andrew", "Abreu, Bryan"), api_pitch_type = c("CH", 
                                                                                                                                     "CU", "FF", "ST", "FF"), `Horizontal Break` = c(14.8485, -8.75612903225807, 
                                                                                                                                                                                     8.8715142198309, -12.5934841628959, -6.10478571428571), `Induced Vertical Break` = c(12.4713, 
                                                                                                                                                                                                                                                                          -4.08215053763441, 16.2903920061491, 4.45031674208145, 16.6883571428571
                                                                                                                                                                                     ), `Pitch Velocity` = c(84.73375, 80.7849462365591, 92.7887009992314, 
                                                                                                                                                                                                             82.9180995475113, 96.6285714285714), pitch_usage = c(16.4812525751957, 
                                                                                                                                                                                                                                                                  11.495673671199, 53.6052740008241, 18.2117840955913, 46.6666666666667
                                                                                                                                                                                                             ), avg_arm_angle = c(43.508, 48.376, 44.82, 44.376, 43.0328947368421
                                                                                                                                                                                                             ), pitch_group = c("Offspeed", "Breaking", "Fastball", "Breaking", 
                                                                                                                                                                                                                                "Fastball"), year = c(2024, 2024, 2024, 2024, 2024), expected_arm_angle = c(45.5588206160552, 
                                                                                                                                                                                                                                                                                                            49.1467520143948, 43.9438816766548, 46.2666308980996, 41.945208160932
                                                                                                                                                                                                                                ), difference = c(-2.0508206160552, -0.770752014394823, 0.876118323345224, 
                                                                                                                                                                                                                                                  -1.8906308980996, 1.08768657591006), difference_percentile = c(44, 
                                                                                                                                                                                                                                                                                                                 19, 24, 43, 30)), row.names = c(NA, -5L), class = c("tbl_df", 
                                                                                                                                                                                                                                                                                                                                                                     "tbl", "data.frame"))


# UI
ui <- fluidPage(
  titlePanel("Arm Angle/Pitch Movement Plots!"),
  
  sidebarLayout(
    sidebarPanel(
      width = 3,
      selectInput("dataset", "Select Dataset:",
                  choices = c("2023 Data" = "2023", "2024 Data" = "2024"),
                  selected = "2024"),
      selectizeInput("pitcher", "Select Pitcher:", choices = NULL)
    ),
    
    mainPanel(
      width = 9,
      reactableOutput("pitcher_table")  # Changed to reactable for better UI
    )
  )
)

# Server
server <- function(input, output, session) {
  
  # Cache the dataset selection to avoid redundant data processing
  dataset_cached <- reactive({
    dataset <- switch(input$dataset,
                      "2023" = final_2023_with_percentile,
                      "2024" = final_2024_with_percentile)
    dataset
  }) %>% bindCache(input$dataset)
  
  # Update pitcher choices based on cached dataset selection
  observe({
    dataset <- dataset_cached()
    pitcher_choices <- unique(dataset$player_name)
    
    updateSelectizeInput(session, "pitcher",
                         choices = pitcher_choices,
                         selected = NULL)  # 切换数据集时重置投手选择
  })
  
  selected_data <- reactive({
    req(input$pitcher)  # 确保投手选择不为空
    dataset <- dataset_cached()
    
    filtered_data <- dataset %>%
      filter(player_name == input$pitcher) %>%
      select(
        Pitcher = player_name,
        `Pitch Type` = api_pitch_type,
        `Horizontal Break`,
        `Induced Vertical Break`,
        `Pitch Velocity`,
        Usage = pitch_usage,
        `Arm Angle` = avg_arm_angle,
        `xArm Angle` = expected_arm_angle,
        Delta = difference,
        `Percentile Difference` = difference_percentile
      )
    
    filtered_data
  }) %>% bindCache(input$dataset, input$pitcher)  # 加入dataset作为缓存依赖
  
  output$pitcher_table <- renderReactable({
    data <- selected_data()
    
    # Round all numeric columns to 1 decimal place
    data <- data %>% mutate(across(where(is.numeric), ~ round(.x, 1)))
    
    reactable::reactable(data, pagination = TRUE)
  }) %>% bindCache(input$dataset, input$pitcher)  # 加入dataset作为缓存依赖
}

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

关键修改点说明： #

• 在selected_data的bindCache中添加了input$dataset，确保切换数据集时重新计算选中投手的数据。
• 在renderReactable的bindCache中添加了input$dataset，确保表格随数据集切换更新。
• 在更新投手选择的observe中加入selected = NULL，切换数据集时清空投手选择，避免无效选择导致空表。
• 给selected_data添加了req(input$pitcher)，避免投手未选择时触发错误。

内容的提问来源于stack exchange，提问作者firmo23