Can not understand the ggplot histogram

user_13815336 0
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I don't understand why my R code give me this error:

data must be a data frame, or other object coercible by fortify(), not a numeric vector.

library(shiny)
library(ggplot2)

ui <- fluidPage(   sliderInput(inputId = "num", 
           label = "Choose a number", 
           value = 25, min = 1, max = 100),   plotOutput("ggplot") )

server <- function(input, output) {   output$ggplot <- renderPlot({
 ggplot(data=rnorm(input$num), aes(input$num)) + geom_histogram()   }) }

shinyApp(ui = ui, server = server)
shiny ggplot2 r
1 Answers

The first argument to ggplot should be a data frame. You have supplied the output of rnorm(), which is a vector. That's the first problem.

The second is that aes() should refer to a column name in the supplied data frame.

I would create a data frame first using input$num. Something like this:

server <- function(input, output) {

  data_df <- data.frame(x = rnorm(as.numeric(input$num)))
  output$ggplot <- renderPlot({
    ggplot(data = data_df, aes(x = x)) + geom_histogram()

  })
}
user_894820
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