R Question
R Shiny error: object input not found
The following code is my Shiny ui:
library(shiny)
shinyUI(fluidPage(
titlePanel("All Country Spend"),
sidebarLayout(
sidebarPanel( selectInput("split",
label = "Choose Fill For the Chart",
choices = c("Action.Obligation","Action_Absolute_Value"),
selected = "Action.Obligation"
)
),
mainPanel(plotOutput("SpendChart"))
)
))
And the following is the server code:
library(shiny)
library(ggplot2)
shinyServer(function(input, output) {
spend <- read.csv("data/Ctrdata.csv")
output$SpendChart <- renderPlot({
Country <- spend$Principal.Place.of.Performance.Country.Name
ggplot(spend, aes(x = Country, y = input$split)) + geom_bar(stat = "identity")
})
})
Every time I run it I get the following error:
"Error in eval(expr, envir, enclos) : object 'input' not found"
I am trying to render a simple bar chart that will toggle between the net and absolute value of contract spending in each country, but it won't recognize my input named "split" from the
selectInputHere is a sample of my data frame:
data.frame(Country = c("Turk", "Turk", "Saudi", "Saudi", "Ger", "Ger"),
Action.Obligation = c(120,-345,565,-454, 343,-565),
Action_Absolute_Value = c(120,345,565,454,343,565))
Answer
The problem is with ggplot evaluating the variable in the context of the data frame provided, spend in your case. What you want is:
ggplot(spend, aes_string(x = "Country", y = input$split))
So your working server.R code is:
library(shiny)
library(ggplot2)
shinyServer(function(input, output) {
spend <- data.frame(Country = c("Turk", "Turk", "Saudi", "Saudi", "Ger", "Ger"),
Action.Obligation = c(120,-345,565,-454, 343,-565),
Action_Absolute_Value = c(120,345,565,454,343,565))
output$SpendChart <- renderPlot({
ggplot(spend, aes_string(x = "Country", y = input$split)) +
geom_bar(stat = "identity")
})
})
Obviously, you can replace the spend df with your CSV import.
Source (Stackoverflow)