sync_plots_quiz_answer

quiz_answer_191227.R

library("shiny")
library("ggplot2")
library("dplyr")

# reference : 
# https://shiny.rstudio.com/gallery/plot-interaction-basic.html
# https://shiny.rstudio.com/gallery/plot-interaction-zoom.html

data <- mtcars %>% mutate(id = 1:n())

my_theme <- 
  theme_bw() + 
  theme(
    legend.position='none',
    panel.grid = element_blank()) 

ui <- fluidPage(
  fluidRow(
    mainPanel(
      h3('How to Sync Plots'),
      code('hint : reactiveValues, observe')
    )
  ),
  fluidRow(
    column(6, plotOutput('plot1', brush=brushOpts(id='brush'))),
    column(6, plotOutput('plot2'))
  )
)

server <- function(input, output) {
  
  # Operation Window Plot 그리기
  output$plot1 <- renderPlot({
    ggplot(data, aes(wt, qsec)) + 
      geom_text(aes(label = id)) + 
      ggtitle(label = "Operation Window") + 
      my_theme
  })
  
  output$plot2 <- renderPlot({
    
    # 드래그로 선택된 데이터
    sel_data <- brushedPoints(data, input$brush)
    data2 <- data %>% mutate(selection = ifelse(id %in% sel_data$id, 1, 0)) 
    
    ggplot(data2) +
      geom_text(aes(x = hp, y = mpg, label = id, color = as.factor(selection))) + 
      ggtitle(label = "Result Window") +
      scale_color_manual(values = c("gray", "red")) +
      my_theme
  })
}

shinyApp(ui, server)