เพิ่มสีให้กราฟ: color input

# Load the colourpicker package
___

ui <- fluidPage(
  sidebarLayout(
    sidebarPanel(
      textInput("title", "Title", "GDP vs life exp"),
      numericInput("size", "Point size", 1, 1),
      checkboxInput("fit", "Add line of best fit", FALSE),

      # Replace the radio buttons with a color input
      radioButtons("color", "Point color",
                   choices = c("blue", "red", "green", "black")),
      selectInput("continents", "Continents",
                  choices = levels(gapminder$continent),
                  multiple = TRUE,
                  selected = "Europe"),
      sliderInput("years", "Years",
                  min(gapminder$year), max(gapminder$year),
                  value = c(1977, 2002))
    ),
    mainPanel(
      plotOutput("plot")
    )
  )
)

# Define the server logic
server <- function(input, output) {
  output$plot <- renderPlot({
    data <- subset(gapminder,
                   continent %in% input$continents &
                   year >= input$years[1] & year <= input$years[2])
    
    p <- ggplot(data, aes(gdpPercap, lifeExp)) +
      geom_point(size = input$size, col = input$color) +
      scale_x_log10() +
      ggtitle(input$title)
    
    if (input$fit) {
      p <- p + geom_smooth(method = "lm")
    }
    p
  })
}

shinyApp(ui = ui, server = server)