Shiny and R combine three graphs into 1 - r

Question

I have developed a basic introductory shiny which downloads stock data and runs 3 technical indicators.
This is the code:
library(shiny)
library(quantmod)
library(dygraphs)
library(TTR)
ui <- shinyUI(fluidPage(
titlePanel("Simple Stock Charting App"),
sidebarLayout(
sidebarPanel(
textInput("symb", label = h3("Input a Valid Stock Ticker"), value = "GE")
),
selectInput("var", label = "bals", choices=list("RSI","Price","ADX")),
### uncomment for dygraphs chart
mainPanel(dygraphOutput("plot"),dygraphOutput("plot2"),dygraphOutput("plot3"))
)
))
server <- shinyServer(function(input, output) {
dataInput <- reactive({
prices <- getSymbols(input$symb, auto.assign = FALSE)
})
output$plot <- renderDygraph({renderPlot
dygraph(Ad(dataInput())) %>%dyRangeSelector()
})
output$plot2 <- renderDygraph({renderPlot
dygraph((RSI(Ad(dataInput()), n = 14))) %>%dyRangeSelector()
})
output$plot3 <- renderDygraph({renderPlot
dygraph((ADX(HLC(dataInput()),n = 14))) %>%dyRangeSelector()
})
})
shinyApp(ui,server)
I would like to know if it is possible the user to choose only of the three indicators each time. Currently, all three are shown but I know its possible to have one graph and based on the selection of the RSI, Value and ADX to change the graph.

Answer 1

You can use switch for what you want:
library(shiny)
library(quantmod)
library(dygraphs)
library(TTR)
ui <- shinyUI(fluidPage(
titlePanel("Simple Stock Charting App"),
sidebarLayout(
sidebarPanel(
textInput("symb", label = h3("Input a Valid Stock Ticker"), value = "GE")
),
selectInput("var", label = "bals", choices=list("RSI","Price","ADX"))
),
### uncomment for dygraphs chart
mainPanel(dygraphOutput("plot"))
))
server <- shinyServer(function(input, output) {
dataInput <- reactive({
getSymbols(input$symb, auto.assign = FALSE)
})
output$plot <- renderDygraph({
data <- switch(input$var,"RSI" = RSI(Ad(dataInput()), n = 14),
"Price" = Ad(dataInput()),
"ADX" = ADX(HLC(dataInput()),n = 14))
dygraph(data) %>%dyRangeSelector()
})
})
shinyApp(ui,server)