使用 Plotly 和 Shiny 在 R 中绘制交互式散点图

Interactive Scatter plot in R using Plotly and Shiny

我对 Shiny 和 Plotly 比较陌生,有以下代码片段:

#
# This is a Shiny web application. You can run the application by clicking
# the 'Run App' button above.
#
# Find out more about building applications with Shiny here:
#
#    http://shiny.rstudio.com/
#

library(shiny)
library(plotly)
library(odbc)
library(DBI)



# Define UI for application that draws a histogram
ui <- fluidPage(

   # Application title
   titlePanel("Demo"),

   #Sidebar with a slider input for number of bins
   sidebarLayout(
      sidebarPanel(
         sliderInput("bins",
                     "Number of bins:",
                     min = 0,
                     max = 100,
                     value = 70)
      ),

      # Show a plot of the generated distribution
      mainPanel(
        tabPanel("Heading", plotlyOutput("tbTable"))

      )
   )
)

# Define server logic required to draw a histogram
server <- function(input, output, session) {

  QueriedData <- reactive({

    connn <- DBI::dbConnect(odbc::odbc(),.connection_string = "XXX", uid = "AB", pwd = "CD")
    lat_rec.df <- dbGetQuery(connn, "PQR")
    dbDisconnect(connn)
    lat_rec.df1
  })  


   output$tbTable <- renderPlotly({

     plot_ly(QueriedData(),x = ~TotalCount, y = ~MyScore, type = 'scatter', mode = 'markers')

  })

}

# Run the application 
shinyApp(ui = ui, server = server)

正如您在上面看到的,我正在绘制我从数据库中读取的数据框的散点图(如反应函数中所述)。我在这里有几个问题:

  1. 我想使用滑块输入作为我的 Y 轴 (MyScore)。我怎么做?我目前无法将 link 滑块(箱)放入我的绘图中。我希望散点图根据滑块输入进行更新。
  2. 我对反应函数有点困惑。这是否意味着每次我更改滑块时,数据库都会被调用(在反应函数中)?它是如何工作的?
  3. 如果我有其他数据库表要在其他区域读取和绘制,我是否将其包含在反应函数中?请指教

在此先感谢您的帮助!干杯!

我solutions/answers对你的三个问题。

1.As您想知道如何使用 sliderInput 控制 Y 轴,下面的代码解释了如何操作。

library(shiny)
library(plotly)
library(DBI)
library(pool)

pool <- dbPool(drv = RMySQL::MySQL(),dbname = "db",host = "localhost",username = "root",password = "psw", port = 3306)
data <- dbGetQuery(pool, "SELECT * FROM testTable;")
ui <- fluidPage(
  titlePanel("Demo"),
  sidebarLayout(
    sidebarPanel(
      sliderInput("bins", "Number of bins:", min = 0, max = 100, value = 70)
    ),
    mainPanel(
      tabPanel("Heading", plotlyOutput("tbTable"), 
               plotOutput("basicPlot") # Added extra as an Example for 3rd question
               )
    )
  )
)
server <- function(input, output, session) {
  QueriedData <- reactive({
    df <- data[data$total <= input$bins,] # filtering datafarme based on sliderInput
    return(df)
  })
  output$tbTable <- renderPlotly({
    plot_ly(QueriedData(), x = ~count, y = ~total, type = 'scatter', mode = 'markers')
  })
  # Added extra as an Example for 3rd question
  output$basicPlot <- renderPlot({
    data_for_plot <- dbGetQuery(pool, "SELECT * FROM dummyTable WHERE uid = 2018;")
    plot(x = data_for_plot$category, y = data_for_plot$performance, type = "p")
  })
}
shinyApp(ui = ui, server = server)

2.For 反应性最好将 table 提取到数据帧中一次,然后将该数据帧放在反应性环境中。这样就可以避免多次数据库调用。您可以检查上面的代码。

3.Using of reactive 环境完全取决于您想要与闪亮的应用程序进行交互时的要求。如果您想从其他 table 获取数据并在不同的图中使用,则无需将数据库连接字符串放在反应​​环境中。只需像上面的代码一样根据您的要求查询数据库。