如何使用R Shiny中的‘parcoord’包将平行坐标图中未选中的轨迹灰显？

library(shiny)
library(parcoords)

ui <- fluidPage(
  titlePanel("Parallel Coordinates Plot with Grayed-Out Unselected Trajectories"),
  sidebarLayout(
    sidebarPanel(
      checkboxGroupInput("select", "Select Trajectories:", choices = c("Trajectory 1", "Trajectory 2", "Trajectory 3"), selected = c("Trajectory 1", "Trajectory 2"))
    ),
    mainPanel(
      parcoordsOutput("plot")
    )
  )
)

server <- function(input, output) {
  data <- data.frame(
    Trajectory = rep(c("Trajectory 1", "Trajectory 2", "Trajectory 3"), each = 5),
    Dim1 = runif(15),
    Dim2 = runif(15),
    Dim3 = runif(15),
    Dim4 = runif(15)
  )
  
  output$plot <- renderParcoords({
    selected_trajectories <- input$select
    all_trajectories <- unique(data$Trajectory)
    
    # Create a color vector for the trajectories
    colors <- ifelse(all_trajectories %in% selected_trajectories, "black", "gray")
    
    parcoords(
      data,
      cols = c("Dim1", "Dim2", "Dim3", "Dim4"),
      rownames = data$Trajectory,
      colnames = c("Dim1", "Dim2", "Dim3", "Dim4"),
      alpha = 0.6,
      brushMode = "1D-axes",
      color = colors
    )
  })
}

shinyApp(ui, server)