Why shiny dashboard is taking too long to load? - r

Question

Objective
Hi, I have two datasets. I want to select one at a time by using radioButtons in shinydashboard.
Problem
In the app.R file, I first load the two data sets (71 Mb and 103 Mb in size). The following code works and only takes few seconds for app to load:
Working Code:
library(shiny)
library(dplyr)
library(shinydashboard)
# Global
df10151 <- read.csv("Data/df1015.csv", header = TRUE)
df8051 <- read.csv("Data/df805.csv", header = TRUE)
# UI
ui <- dashboardPage(
dashboardHeader(title = "Driving States"),
dashboardSidebar(
sliderInput("fid", "Frame ID:",
min = 0, max = 50, value = 3, step = 0.1
)))
# Server
server <- function(input, output, session) {
}
shinyApp(ui, server)
But when I add the radioButtons, it takes forever and doesn't load:
Failing Code:
library(shiny)
library(dplyr)
library(shinydashboard)
# Global
df10151 <- read.csv("Data/df1015.csv", header = TRUE)
df8051 <- read.csv("Data/df805.csv", header = TRUE)
# UI
ui <- dashboardPage(
dashboardHeader(title = "Driving States"),
dashboardSidebar(
radioButtons("radio", label = h3("Select the Dataset (first 5 minutes)"),
choices = list("US-101" = df10151, "I-80" = df8051),
selected = NULL),
sliderInput("fid", "Frame ID:",
min = 0, max = 50, value = 3, step = 0.1
)))
# Server
server <- function(input, output, session) {
}
shinyApp(ui, server)
There is no error message. What am I doing wrong?

Answer 1

I am not sure what exactly you would like to plot, so here is an example:
Radiobutton in ui.R will work like:
radioButtons("radio", label = h3("Select the Dataset (first 5 minutes)"),
choices = c("US-101" = 1, "I-80" = 2),
selected = 1)
For server.R you need something like:
output$plot = renderPlot({
switch(input$radio,
`1` = hist(df10151$Var),
`2` = hist(df8051$Var)
})