How to plot in rshiny depending on the columns I choose - r

Question

I have made a shiny app which takes in any data and shows column names depending on the data.
c1 <- rnorm(10,0,1)
c2 <- c(rep("txA",5),rep("txB",5))
c3 <- c(1:4,1:4,1:2)
c4 <- rep(LETTERS[1:5],2)
mydata <- data.frame(c1,c2,c3,c4)
ui <- fluidPage(
fileInput(inputId = "file",
label = "import file"),
tableOutput("tb"),
sidebarLayout(
sidebarPanel(
uiOutput(outputId = "aa")
),
mainPanel(textOutput("a"),
verbatimTextOutput("info"),
verbatimTextOutput("summary"),
plotOutput("plot", click = "plot_click")
)
)
)
server <- function(input,output) {
output$aa <- renderUI({
validate(need(input$file != "", ""))
mydata <- read.csv(input$file$datapath)
selectInput(inputId = "aa", #can be any name?
label="Select:",
choices = colnames(mydata))
})
output$tb <- renderTable({
data <- input$file
if (is.null(data))return()
read.table(data$datapath,sep=",")
})
output$summary <- renderPrint({
summary(mydata)
})
output$plot <- renderPlot({
plot(mydata)
})
output$info <- renderText({
paste0("x=", input$plot_click$x, "\ny=", input$plot_click$y)
})
}
shinyApp(ui=ui, server=server)
If I run this I get the following:
I am trying to make a shiny app which shows a basic plot depending on the columns that I choose. How would I do this?

Answer 1

Something like this would do, make sure to uncomment the file input
library(shiny)
c1 <- rnorm(10,0,1)
c2 <- c(rep("txA",5),rep("txB",5))
c3 <- c(1:4,1:4,1:2)
c4 <- rep(LETTERS[1:5],2)
mydata <- data.frame(c1,c2,c3,c4)
ui <- fluidPage(
fileInput(inputId = "file",
label = "import file"),
tableOutput("tb"),
sidebarLayout(
sidebarPanel(
uiOutput(outputId = "aa")
),
mainPanel(textOutput("a"),
verbatimTextOutput("info"),
verbatimTextOutput("summary"),
plotOutput("plot", click = "plot_click")
)
)
)
server <- function(input,output) {
output$aa <- renderUI({
#validate(need(input$file != "", ""))
#mydata <- read.csv(input$file$datapath)
## Since your output$aa already has name aa you cant use it twice!
selectInput(inputId = "aa2", #can be any name?
label="Select:",
choices = colnames(mydata))
})
output$tb <- renderTable({
data <- input$file
if (is.null(data))return()
read.table(data$datapath,sep=",")
})
mysubsetdata <- eventReactive(input$aa2,{
mydata[[input$aa2]]
})
output$summary <- renderPrint({
summary(mysubsetdata())
})
output$plot <- renderPlot({
plot(mysubsetdata())
})
output$info <- renderText({
paste0("x=", input$plot_click$x, "\ny=", input$plot_click$y)
})
}
shinyApp(ui=ui, server=server)
Added eventReactive to listen to selectInput
All widgets must have unique id so you cannot use aa twice, one for renderui and one for selectInput