equatiomatic-shiny.R

library(shiny)
library(shinyWidgets)
library(ggplot2)
library(equatiomatic)
library(gtsummary)
library(gt)

ui <- fluidPage(
  titlePanel("equatiomatic w/Shiny"),
  sidebarLayout(
    sidebarPanel(
      multiInput(
        inputId = "xvars", label = "Select predictor variables :",
        choices = names(mpg)[-8],
        selected = "displ"
      )
    ),
    
    mainPanel(
      uiOutput("eq"),
      gt_output("tbl")
    )
  )
)

server <- function(input, output) {
  
  model <- reactive({
    form <- paste("hwy ~ ", paste(input$xvars, collapse = " + "))
    lm(as.formula(form), mpg)
  })
  
  output$eq <- renderUI(
    withMathJax(
      helpText(
        equatiomatic:::format.equation(
          extract_eq(model(), wrap = TRUE, terms_per_line = 3)
        )
      )
    )
  )
  
  output$tbl <- render_gt({
    as_gt(tbl_regression(model()))
  })
  
}

shinyApp(ui = ui, server = server)