Display multiple plotly plots in Shiny (only one appears)

Question

I am trying to plot two plotly pie charts side by side in the Shiny main panel, but only the last one shows up. However, the two plots could be produced without problem individually.

As an example, my code below. Starting from the mtcars dataset, I created two extra columns listing the manufacturer and random categories (Sport and Sedan).

mtcars$manuf <- unlist(strsplit(rownames(mtcars), " "))[1]
mtcars$Category <- c(rep("Sport", 22), rep("Sedan", 10))
head(mtcars)
                   mpg cyl disp  hp drat    wt  qsec vs am gear carb manuf   Cat
Mazda RX4         21.0   6  160 110 3.90 2.620 16.46  0  1    4    4 Mazda Sport
Mazda RX4 Wag     21.0   6  160 110 3.90 2.875 17.02  0  1    4    4 Mazda Sport
Datsun 710        22.8   4  108  93 3.85 2.320 18.61  1  1    4    1 Mazda Sport
Hornet 4 Drive    21.4   6  258 110 3.08 3.215 19.44  1  0    3    1 Mazda Sport
Hornet Sportabout 18.7   8  360 175 3.15 3.440 17.02  0  0    3    2 Mazda Sport
Valiant           18.1   6  225 105 2.76 3.460 20.22  1  0    3    1 Mazda Sport

From there, the app user can choose between ligth (mtcars$wt < 3) and heavy (mtcars$wt >=3) cars.

My app.R:

library(shiny)
library(plotly)
library(dplyr)


mtcars$manuf <- unlist(strsplit(rownames(mtcars), " "))[1]
mtcars$Category <- c(rep("Sport", 22), rep("Sedan", 10))


ui <- fluidPage(

    sidebarLayout(
        sidebarPanel(     
            selectInput(
                inputId = "select",
                label = "Select car weigth:",
                choices = c("All","light","heavy")
            ),                
        ),

        mainPanel(
            plotlyOutput("view")
        )
    )
)

server <- function(input, output) {
    dataset <- reactive({
        switch(input$select,
            "All" = mtcars,
            "light" = subset(mtcars, wt < 3),
            "heavy" = subset(mtcars, wt >= 3)
        )
    })

    output$view <- renderPlotly({

        # First plot
        df1 <- dataset() %>% group_by(manuf)
        df1 <- df1 %>% summarize(count=n())
        fig1 <- df1 %>% plot_ly(labels = ~manuf, values = ~count)
        fig1 <- fig1 %>% add_pie(hole = 0.6)
        fig1 <- fig1 %>% layout(title = "Manufacturers",showlegend = F)

        # Second plot
        df2 <- dataset() %>% group_by(Category)
        df2 <- df2 %>% summarize(count=n())
        fig2 <- df2 %>% plot_ly(labels = ~Category, values = ~count)
        fig2 <- fig2 %>% add_pie(hole = 0.6)
        fig2 <- fig2 %>% layout(title = "Categories",showlegend = F)

        # Grouped plots
        subplot(fig1, fig2)
    })
}

shinyApp(ui = ui, server = server)

Any help would be greatly appreciated :-)

Answer 1

Include this and give it a try:

     fig<-subplot(fig1,fig2)
     fig