shiny-ui-server.R

selected_data <- reactive({
  iris[, c(input$xcol, input$ycol)]
})

clusters <- reactive({
  kmeans(selected_data(), input$clusters)
})

output$plot1 <- renderPlot({
  palette(c(
    "#E41A1C", "#377EB8", "#4DAF4A", "#984EA3",
    "#FF7F00", "#FFFF33", "#A65628", "#F781BF", "#999999"
  ))

  par(mar = c(5.1, 4.1, 0, 1))
  plot(selected_data(),
    col = clusters()$cluster,
    pch = 20, cex = 3
  )
  points(clusters()$centers, pch = 4, cex = 4, lwd = 4)
})