CODEWITHSUNDEEP
rshinydplyrsubset
Mathieu P.
Mathieu P.

Reputation: 3

R shiny : simultaneous filter on variable name and value

I am trying to buil a shiny app that returns a graph based on triplet (variable, min, max) selected by the user. I probably miss something in the war shint and dplyr evaluate statements, but my instinctive way of doing this does not work. A condition on the type : filter(iris, input$variable >= input$range[1] & input$variable <= input$range[2] leads no an empty dataset.

Here is an example with the iris dataset: 

library(shiny)
library(tidyverse)

    ui <- fluidPage(
 titlePanel("Filter example"),

   sidebarLayout(
      sidebarPanel(
         sliderInput("dimension",
                     "Dimension:",
                     min = 1,
                     max = 8,
                     value = c(1,8)),
         selectInput("Petal or Sepal", "type", 
                     c("Sepal Length" = "Sepal.Length",
                       "Petal Length" = "Petal.length"))
      ),

      mainPanel(
         plotOutput("distPlot")
      )
   )
)

server <- function(input, output) {

   plotdata <- reactive({
     filter(iris, input$type <= input$dimension[1] & input$type >= input$dimension[2])
   })

   output$distPlot <- renderPlot({

    MyPlot <-  ggplot(data = plotdata(),
            mapping = aes(x = Sepal.Width, fill = Species))
    Myplot + geom_histogram()
   })
}

shinyApp(ui = ui, server = server)

The issue is obviously in the 

plotdata <- reactive({
         filter(iris, input$type <= input$dimension[1] & input$type >= input$dimension[2])
       })

statement, but after hours of trawling though StackOverflow, I could not find a solution.

Thans for your help

Upvotes: 0

Views: 44

Answers (1)

ozanstats
ozanstats

Reputation: 2864

There are some parameter mismatches and typos in the example code. Your filtering implementation also has issues. The following should work:

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

ui <- fluidPage(
  titlePanel("Filter example"),
  sidebarLayout(
    sidebarPanel(
      sliderInput(
        inputId = "dimension",
        label = "Dimension:",
        min = 1,
        max = 8,
        value = c(1,8)),
      selectInput(
        inputId = "type", 
        label = "Petal or Sepal",
        choices = c(
          "Sepal Length" = "Sepal.Length",
          "Petal Length" = "Petal.Length"
        )
      )
    ),
    mainPanel(
      plotOutput("distPlot")
    )
  )
)

server <- function(input, output) {

  plotdata <- reactive({
    iris[(iris[ , input$type] >= input$dimension[1] & iris[ , input$type] <= input$dimension[2]), ]
  })

  output$distPlot <- renderPlot({
    ggplot(
      data = plotdata(),
      mapping = aes(x = Sepal.Width, fill = Species)
    ) + 
      geom_histogram()
  })
}

shinyApp(ui = ui, server = server)

Upvotes: 1

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