product() in geom_mosaic() not accepting reactive inputs on R Shiny?

Question

I'm playing around with the geom_mosaic() function (part of the ggmosaic package) on R Shiny and came up with a problem I've been trying to solve for a few days.

First, some sample data:

a <- "a"
b <- "b" 
c <- "c"

df <- tribble(
  ~id, ~var1, ~var2, ~var3, 
  1, a, b, c,
  2, b, b, c,
  3, b, b, c,
  4, a, c, b, 
  5, a, a, a,
  6, b, c, c, 
  7, b, c, a,
  8, a, a, b,
  9, a, a, a, 
  10, b, b, c
)

It seems that geom_mosaic() isn't accepting reactive inputs on Shiny, i.e. Code 1 (below) works fine on the R console, but Code 2 (the R Shiny equivalent) isn't working, giving the following Error message:

Error: object ______ not found

Code 1 (geom_mosaic works fine on console):

library(tidyverse)
library(ggmosaic)

selected_var1 <- "var1"
selected_var1_dat <- df[[selected_var1]]

selected_var2 <- "var2"
selected_var2_dat <- df[[selected_var2]]

ggplot(data = df) + 
  geom_mosaic(aes(x = product(selected_var1_dat), 
                  fill = selected_var2_dat, na.rm = T))

Output ggplot (everything looks good):

Code 2 (now, to implement in Shiny):


library(shiny) 
library(tidyverse)
library(ggmosaic)

varOptions <- c("var1", "var2", "var3")
a <- "a"
b <- "b"
c <- "c"

df <- tribble(
  ~id, ~var1, ~var2, ~var3, 
  1, a, b, c,
  2, b, b, c,
  3, b, b, c,
  4, a, c, b, 
  5, a, a, a,
  6, b, c, c, 
  7, b, c, a,
  8, a, a, b,
  9, a, a, a, 
  10, b, b, c
)

ui <- fluidPage(
  sidebarLayout(
    sidebarPanel(
      selectInput(inputId = "selected_var1",
                  label = "X:",
                  choices = varOptions),
      selectInput(inputId = "selected_var2",
                  label = "Y:", 
                  choices = varOptions)
    ),
    mainPanel(
      plotlyOutput(outputId = "mosaic")
    )
  )
)

server <- function(input, output) {
  output$mosaic <- renderPlotly({

    selected_var1 <- input$selected_var1
    selected_var1_dat <- df[[selected_var1]]

    selected_var2 <- input$selected_var2
    selected_var2_dat <- df[[selected_var2]]

    ggplot(data = df) + 
      geom_mosaic(aes(x = product(selected_var1_dat), 
                      fill = selected_var2_dat, na.rm = T))

  })
}

shinyApp(ui = ui, server = server)

Which outputs this error message:

I've tried different ways to get around this problem with no luck. I've worked with Shiny quite a bit and it seems to work with every other ggplot graph I've used. Does anyone have any ideas on what might be going on?

score 0 · Answer 1 · answered Mar 02 '19 at 02:17

0

I haven't fully figured this out, but your app works well if you:

Run the code preceding the ui / server part
Enter selected_var1_dat = df[["var1"]] and selected_var1_dat = df[["var2"]] in the console
Run the app

So the problem seems to be that in your server code, selected_var1_dat <- df[[selected_var1]] produces no result, which suggests that selected_var1 <- input$selected_var1 produces no result.

answered Mar 02 '19 at 02:17

user2363777

947
8
18

I noticed this too! Although I've tried with other graphs, and `selected_var1_dat <- df[[selected_var1]]` does produce a result. That's why I think maybe it's the `product()` function that's required by `geom_mosaic()` that's causing the problem? – Felix T. Mar 04 '19 at 16:03

Haley · Accepted Answer · 2019-03-04T22:42:11.053

ggmosaic and plotly are not compatible currently. You can get your app to work without plotly with the following code.

library(shiny) 
library(tidyverse)
library(ggmosaic)
#library(plotly)

a <- "a"
b <- "b"
c <- "c"

df <- tribble(
  ~id, ~var1, ~var2, ~var3, 
  1, a, b, c,
  2, b, b, c,
  3, b, b, c,
  4, a, c, b, 
  5, a, a, a,
  6, b, c, c, 
  7, b, c, a,
  8, a, a, b,
  9, a, a, a, 
  10, b, b, c
)

ui <- fluidPage(
  sidebarLayout(
    sidebarPanel(
      selectInput(inputId = "selected_var1",
                  label = "X:",
                  choices = names(df)[-1]),
      selectInput(inputId = "selected_var2",
                  label = "Y:", 
                  choices = names(df)[-1])
    ),
    mainPanel(
      plotOutput(outputId = "mosaic")
    )
  )
)

server <- function(input, output) {

  output$mosaic <- renderPlot({
    ggplot(data = df) + 
      geom_mosaic(aes(x = product(!!sym(input$selected_var1)), 
                      fill = !!sym(input$selected_var2)))
  })
}

shinyApp(ui = ui, server = server)

Also-- for anyone who cares, [this SO thread](https://stackoverflow.com/questions/19233365/how-to-create-a-marimekko-mosaic-plot-in-ggplot2) offers a great discussion on mosaic plots and different alternatives to geom_mosaic(). I'll be using this to implement on shiny until the geom_mosaic() / ggplotly() interaction is up and running again! — Felix T., Mar 04 '19 at 22:53

product() in geom_mosaic() not accepting reactive inputs on R Shiny?

2 Answers2