Question

我有这个用于K-Means聚类的应用程序。我希望用户使用ggplot2选择一个selectInput主题。用户将看到一个下拉菜单，并为其情节选择一个主题。

这是我尝试过的：


###################################################################################################################
# Shiny App
###################################################################################################################
ui <- navbarPage("Clustering Demo",
                 tabPanel("K-Means", icon = icon("folder-open"),
                          sidebarLayout(
                            sidebarPanel(
                              sliderInput("num_centers", 
                                          label = h4("Select K (# of Clusters)"),
                                          min = 2,
                                          max = 10,
                                          value = 2),
                              selectInput("theme", label = h4("Select theme for plot"),
                                          choices = list("Light" = theme_light(),
                                                         "Minimal" = theme_minimal()))

                            ),
                            mainPanel(
                              plotOutput("kmeans"))
                          )
                 )
)



server <- function(input, output, session) {

  # K-Means Algorithm
  k_centers <- reactive({kmeans(x = harvard_scaled, centers = input$num_centers)})

  plot_theme <- reactive({input$theme})

  output$kmeans <- renderPlot({

    # Require number of centers
    req(input$num_centers)

    # K Means augmented dataset
    harvard_cluster <- augment(k_centers(), harvard_processed)

    # Static Plot 
    harvard_cluster %>% 
      janitor::clean_names() %>% 
      ggplot(aes(nevents, nplay_video, color = cluster)) +
      geom_point() +
      labs(x = "# of interactions with the course",
           y = "# of play video events",
           color = "Cluster") +
      xlim(0, 52000) +
      ylim(0, 12500) +
      ggtitle(paste("K-Means Clustering of students where", "K =", input$num_centers)) +
      plot_theme()
  })

}




# Create Shiny app object
shinyApp(ui = ui, server = server)

示例数据集：harvard_scaled

harvard_scaled <- structure(c(0.150884824647657, 0.150884824647657, 0.449543446630647, 
0.217253407310543, -0.230734525663942, -0.330287399658272, -0.960788934955696, 
0.715017777282194, 0.449543446630647, -0.147773797335334, -0.380063836655437, 
-0.612353875975541, -0.463024564984046, -0.811459623964201, -1.60788261591884, 
-1.60788261591884, -0.89442035229281, 2.04238943053993, 1.7105465172255, 
2.29127161552575, 0.233845552976265, -0.761683186967036, -0.811459623964201, 
-1.12671039161291, -0.147773797335334, 1.19619000158812, 0.980492107933741, 
1.7105465172255, -0.711906749969871, -0.0648130690067253, -0.844643915295645, 
0.217253407310543, -0.570619818667904, -0.570619818667904, -0.990182090888924, 
0.22009369436402, 1.04308122833602, -0.046166978391628, 1.04308122833602, 
-0.677930938293665, -0.725535119180281, -0.509299178881755, -0.509299178881755, 
0.363713087547369, 0.363713087547369, 0.363713087547369, 1.94675381465822, 
1.84993175183798, 1.68856164713759, -1.226589294275, -1.25079480998006, 
-1.28790993406115, -0.892553177545187, 0.704204008465197, 0.591244935174923, 
0.962396175985825, 1.36582143773681, -1.22416874270449, -0.890939476498183, 
-1.09426580842068, 0.970464681220845, -0.691647397193198, 0.567039419469864, 
-0.885291522833669), .Dim = c(32L, 2L), .Dimnames = list(c("Mazda RX4", 
"Mazda RX4 Wag", "Datsun 710", "Hornet 4 Drive", "Hornet Sportabout", 
"Valiant", "Duster 360", "Merc 240D", "Merc 230", "Merc 280", 
"Merc 280C", "Merc 450SE", "Merc 450SL", "Merc 450SLC", "Cadillac Fleetwood", 
"Lincoln Continental", "Chrysler Imperial", "Fiat 128", "Honda Civic", 
"Toyota Corolla", "Toyota Corona", "Dodge Challenger", "AMC Javelin", 
"Camaro Z28", "Pontiac Firebird", "Fiat X1-9", "Porsche 914-2", 
"Lotus Europa", "Ford Pantera L", "Ferrari Dino", "Maserati Bora", 
"Volvo 142E"), c("mpg", "disp")), "`scaled:center`" = c(mpg = 20.090625, 
disp = 230.721875), "`scaled:scale`" = c(mpg = 6.0269480520891, 
disp = 123.938693831382))

示例数据集：harvard_processed

harvard_processed <- structure(list(mpg = c(21, 21, 22.8, 21.4, 18.7, 18.1, 14.3, 
24.4, 22.8, 19.2, 17.8, 16.4, 17.3, 15.2, 10.4, 10.4, 14.7, 32.4, 
30.4, 33.9, 21.5, 15.5, 15.2, 13.3, 19.2, 27.3, 26, 30.4, 15.8, 
19.7, 15, 21.4), disp = c(160, 160, 108, 258, 360, 225, 360, 
146.7, 140.8, 167.6, 167.6, 275.8, 275.8, 275.8, 472, 460, 440, 
78.7, 75.7, 71.1, 120.1, 318, 304, 350, 400, 79, 120.3, 95.1, 
351, 145, 301, 121)), row.names = c("Mazda RX4", "Mazda RX4 Wag", 
"Datsun 710", "Hornet 4 Drive", "Hornet Sportabout", "Valiant", 
"Duster 360", "Merc 240D", "Merc 230", "Merc 280", "Merc 280C", 
"Merc 450SE", "Merc 450SL", "Merc 450SLC", "Cadillac Fleetwood", 
"Lincoln Continental", "Chrysler Imperial", "Fiat 128", "Honda Civic", 
"Toyota Corolla", "Toyota Corona", "Dodge Challenger", "AMC Javelin", 
"Camaro Z28", "Pontiac Firebird", "Fiat X1-9", "Porsche 914-2", 
"Lotus Europa", "Ford Pantera L", "Ferrari Dino", "Maserati Bora", 
"Volvo 142E"), class = "data.frame")

Answer 1

如果单击主题选择的下拉菜单，您可能会发现它看起来不像您期望的那样。您不能在UI层中存储非原子对象。在代码中的其他位置定义主题列表并将其用作查找会更容易。例如

themes <- list("Light" = theme_light(),
               "Minimal" = theme_minimal())

ui <- navbarPage(..., 
   selectInput("theme", label = h4("Select theme for plot"), choices = names(themes)), 
   ...)

server <- function(input, output, session) {
   ...
   plot_theme <- reactive({themes[[input$theme]]})
   ...
}

修改闪亮的ggplot主题

1 个答案: