Using autoplotly in shiny app with user selected columns

Question

I am making a shiny app that allows the user to upload a CSV, then select the independent and dependent variables. Right now I am able to upload a file, select variables and run regression analysis. But, I am stuck at the step where I would pass the lm object to autoplot then making it interactive via autoplotly in a new tab. How can I create interactive regression plots via using user selected variables in a shiny app?

UI

ui = navbarPage(tabPanel("Regression Analysis",
                         dataTableOutput('mytable'),
                         sidebarLayout(
                           sidebarPanel(width=3, fileInput("file1", "Please choose a CSV file",
                                                              multiple = T,
                                                              accept = c("text/csv",
                                                                         "text/comma-separated-values,text/plain",
                                                                         ".csv")),
                                                    tags$hr(),
                                                    checkboxInput("header", "Header", TRUE),
                                                    radioButtons("sep", "Separator",
                                                                 choices = c(Comma = ",",
                                                                             Semicolon = ";",
                                                                             Tab = "\t"),
                                                                 selected = ","),
                                                    radioButtons("quote", "Quote",
                                                                 choices = c(None = "",
                                                                             "Double Quote" = '"',
                                                                             "Single Quote" = "'"),
                                                                 selected = '"'),
                                                    tags$hr(),
                                                    radioButtons("disp", "Display",
                                                                 choices = c(Head = "head",
                                                                             All = "all"),
                                                                 selected = "head")

                           ),

                           mainPanel(
                             tableOutput("contents"),
                             actionButton("choice", "Define Regression Variables"),
                             selectInput("independent", "Independent Variables:", choices = NULL, multiple = T),
                             uiOutput("dependent1"),
                             #tableOutput("Table_selected.col"),
                             verbatimTextOutput("regTab")
                           )
                         ),
tabPanel("Plots",
    icon = icon("chart-area"),
    plotlyOutput(outputId = "RegPlots"))

)

Server

server = function(input, output, session) {

  mydf <- reactive({
    # input$file1 will be NULL initially. After the user selects
    # and uploads a file, head of that data file by default,
    # or all rows if selected, will be shown.

    req(input$file1)

    df = read.csv(input$file1$datapath,
                  header = input$header,
                  sep = input$sep,
                  quote = input$quote)

    if(input$disp == "head") {
      return(head(df))
    }
    else {
      return(df)
    }

  })

  output$contents = renderTable({
    req(mydf())
    mydf()
  })

  # Code for allowing the user to select the variables/columns of interest
  info <- eventReactive(input$choice, {
    req(mydf())
    f <- mydf()
    f
  })

  observeEvent(input$choice, {  ## to update only when you click on the actionButton
    req(info())
    updateSelectInput(session,"independent", "Please Select independent Variable(s):", choices = names(info()) )
  })


  # output$Table_selected.col <- renderTable({
  #   input$choice
  #   req(info(),input$columns)
  #   f = info()
  #   f = subset(f, select = input$columns) #subsetting takes place here
  #   head(f)
  # })

  output$dependent1 = renderUI({
    req(mydf(),input$independent)
    radioButtons("dependent1", "Select a dependent Variable:",choices=names(mydf())[!names(mydf()) %in% input$independent])
  })

  ###  need to build your formuila correctly; It will work with multiple independent variables
  ###  model <- reactive({lm(reformulate(input$IndVar, input$DepVar), data = RegData)})

  runRegression <- reactive({
    req(mydf(),input$independent,input$dependent1)
    a = lm(reformulate(input$independent, input$dependent1), data=mydf())
    a
    # multinom(reformulate(input$independent, input$dependent1), data=mydf())  ### mulitnomial from nnet package
  })

  output$regTab = renderPrint({
    req(runRegression())
    if(!is.null(input$independent)){
      summary(runRegression())
    } else {
      print(data.frame(Warning="Please select Model Parameters."))
    }
  })

}
output$RegPlots = renderPlotly({
      req(runRegression())
      # Plot the residuals
      lm.plot.rsd = autoplot(a, label.size = 3, which = 1) +
        theme_bw()
      autoplotly(lm.plot.rsd +
                   ggplot2::ggtitle("Residuals vs Fitted")) 
    })
shinyApp(ui, server)

Error

 Error in : Objects of type function not supported by autoplot.

Answer 1

Try this

  output$RegPlots = renderPlot({
    req(runRegression())
    # Plot the residuals
    a =  runRegression()
    ggplot(a, aes(x = .fitted, y = .resid)) +
      geom_point() +
      geom_smooth(method = loess, formula = y ~ x) +
      labs(title="Residuals vs Fitted")
     
  })

You can try other plots if you want.