Generate multiple plots based on checkboxes clicked in Shiny

Question

I am trying to make shiny app.

I want my app to generate multiple plots based on number of check box clicked. Iris is the dataframe which has various quantitative variables and i am trying to dynamically generate density plots of 4 variables which are in iris. Below is my server and ui page till now.

library(shiny)
library(ggplot2)
library(tidyverse)


df<-iris[,colnames(iris)!="Species"]

ui<-fluidPage(

titlePanel("Density Plots of Quantitative Variables"),
sidebarLayout( sidebarPanel( sliderInput("bw","Slide to change bandwidth 
                                         of Plot",min=0.1,max=20,value=3,step=0.1,animate=TRUE),

                             checkboxGroupInput("variableinp","Choose variables",
                                                choices=colnames(df),selected = colnames(df)[1]),verbatimTextOutput("value")
),
mainPanel( plotOutput("densityplot"))
)
)


server<-function(input,output){

# observeEvent(input$variableinp, {
#      print((input$variableinp))
#  })

output$densityplot <- renderPlot({

    if(!is.null(input$variableinp)) {

        getoutandquant <- function(x) {
            q1<-quantile(x)[[2]]
            q3<-quantile(x)[[4]]
            IQR<-q3-q1

            out1<-q3+(1.5)*IQR
            out2<-q1-(1.5)*IQR

            #Finding the list of points which are outliers for a particular 
           variable.
            out<-x[x>out1]
            out2<-x[x<out2]
            outliers<-tibble(x=c(out,out2),y=0)

            return(outliers)
        }
        nplot<-length(input$variableinp)
        x<-input$variableinp

        for ( i in 1:nplot) {
            outlier<-getoutandquant(df[,x[i]])

        }    

        p1<-ggplot(df,aes_string(input$variableinp[i]))+
            stat_density(geom="line",adjust=input$bw)+ ylab("Density\n")
        p1+geom_point(data=outlier,aes(x,y),shape=23)
    }
})
}


shinyApp(ui=ui,server=server)

Below is my output as far. As it can be seen only one plot is generated. With 2 check boxes checked I would like 2 plots, with 3 checkbox 3 plots and so on. :

Can anyone give me hints or any lead to on how should i do it. My plots are generating good. I just need the multiple plots to be produced based on number of checkboxes clicked.

Your code can not work properly, please modified what you have done so far, and use dput to post your dataframe. — Jim Chen
@VisheshShrivastav I have included iris data sets to start with. — Naveen Gabriel
@JimChen Obviously it is not working. I need multiple plots I have included iris datasets as an example. — Naveen Gabriel

Jim Chen Jim Chen · Accepted Answer · 2018-09-15T17:08:02

Try to store your ggplot output in a list, then use do.call and grid.arrange to combine all of it into one plot:

Try the following code, it should run perfectly: You should install gridExtra package to combine multiple ggplot.

library(shiny)
library(ggplot2)
library(tidyverse)
library(gridExtra)

df<-iris[,colnames(iris)!="Species"]

ui<-fluidPage(

  titlePanel("Density Plots of Quantitative Variables"),
  sidebarLayout( sidebarPanel( sliderInput("bw","Slide to change bandwidth 
                                           of Plot",min=0.1,max=20,value=3,step=0.1,animate=TRUE),

                               checkboxGroupInput("variableinp","Choose variables",
                                                  choices=colnames(df),selected = colnames(df)[1]),verbatimTextOutput("value")
  ),
  mainPanel( plotOutput("densityplot"))
  )
  )


server<-function(input,output){

  # observeEvent(input$variableinp, {
  #      print((input$variableinp))
  #  })

  output$densityplot <- renderPlot({

    if(!is.null(input$variableinp)) {

      getoutandquant <- function(x) {
        q1<-quantile(x)[[2]]
        q3<-quantile(x)[[4]]
        IQR<-q3-q1

        out1<-q3+(1.5)*IQR
        out2<-q1-(1.5)*IQR

        #Finding the list of points which are outliers for a particular 
        out<-x[x>out1]
        out2<-x[x<out2]
        outliers<-tibble(x=c(out,out2),y=0)

        return(outliers)
      }
      nplot<-length(input$variableinp)
      x<-input$variableinp

      p<-list()
      for ( i in 1:nplot) {
        outlier<-getoutandquant(df[,x[i]])
        p[[i]]<-ggplot(df,aes_string(input$variableinp[i]))+
          stat_density(geom="line",adjust=input$bw)+ ylab("Density\n")+
          geom_point(data=outlier,aes(x,y),shape=23)
      }    
      do.call(grid.arrange,p)
    }
  })
}


shinyApp(ui=ui,server=server)

Also , please select this post as the best answer if it solved your problem, thanks a million.

Generate multiple plots based on checkboxes clicked in Shiny

1 Answers