title: How to make action button refreshing the plot?
body: <p>I want the plot to refresh only after: changing the sliders and pressing the actionbutton. I don't want the plot to refhres after changing radioButton. How can I do this? I tried this:</p>
  
  <pre><code>library(shiny)
  library(ggplot2)
  
  #data change only once at the begenin
  dt &lt;- data.frame(x=runif(100), y=runif(100))
  
  
  ui &lt;- fluidPage(
    sliderInput("slider1","slider1", value=5, min=1, max=10),
    sliderInput("slider2","slider2", value=0.8, min=0, max=1),
    radioButtons("check1","check1",choices = c("red","blue","green")),
    actionButton("refreshColours","refreshColours"),
    plotOutput("rys")
  )
  
  
  server &lt;- function(input,output){
  
    pp &lt;- reactive({
      ggplot(dt, aes(x,y)) + 
        geom_point(size=input$slider1, alpha=input$slider2, colour=isolate(input$check1))
    })
  
    pp &lt;- eventReactive(input$refreshColours{pp})
  
    output$rys &lt;- renderPlot({
      pp()
    })
  
  }
  
  
  shinyApp(ui=ui, server=server)
  </code></pre>
  
  <p>but I don't know how to refresh plot after pressing the action button.</p>