Move the "Decision Threshold" without redrawing everything?

[ignacio82]

First, I'm not sure if this is possible or not. Right now whenever you change the threshold in a shiny app, the whole figure gets redrawn from scratch. This is a bit misleading because the threshold does not affect the rest of the figure. This is a basic example:

## app.R ##
library(shiny)
library(shinydashboard)
library(IMPosterior) 
set.seed(9782)
x <- rnorm(n = 1000, mean = 3, sd = 2)

ui <- dashboardPage(
  dashboardHeader(),
  dashboardSidebar(
    sliderInput(
      "threshold",
      h4("Decision Threshold:"),
      min = 50,
      max = 99,
      value = 75,
      step = 1,
      post = "%"
    )
  ),
  dashboardBody(
    box(
      title = "Posterior Distribution",
      status = "primary",
      solidHeader = TRUE,
      width = 6,
      IMPosteriorOutput("plot", width = "100%")
    )
  )
)

server <- function(input, output) { 
  
  output$plot <- renderIMPosterior({
    p <- IMPosterior(x = x, MME = 1, threshold = input$threshold/100)
    return(p)
  })
  
}

shinyApp(ui, server)