Bdtjtk

I am new to Shiny Notebooks in R. I'm just tinkering around trying to learn. I am trying to get a ggplot to look right in the HTML document output, but I cannot get the scaling correct. If I run the same ggplot in the Shiny notebook without using input variables it looks the way I would expect. Why does this happen?

The follow code produces an output that is unusable:

```{r selectInput for iris database}



selectInput("x_axis", "X-Axis",

            choices = names(iris))

selectInput(inputId = "y_axis", label = "Y-Axis",

            choices = names(iris))



renderPlot({

  ggplot(iris, aes(input$x_axis, input$y_axis, colour = Species)) +

      geom_point()

})

The following code works correctly:

##GGPLOT Example

```{r}



ggplot(iris, aes(Petal.Length, Sepal.Length, colour = Species)) + 

                xlim(0,10) +

                ylim(0,10) +

                geom_point()

```

You shouldn't be providing options to aes using [, [[ or $ as ggplot expects bare variable names within aes. For this instance aes_string is provided where you can provides the aes a string values, which works well with selectInput from shiny.

The chunk below should work when rendered in a notebook with runtime: shiny

```{r selectInput for iris database, echo = FALSE, message = FALSE}

library(tidyverse)

library(shiny)



selectInput("x_axis", "X-Axis",

            choices = names(iris))



selectInput(inputId = "y_axis", label = "Y-Axis",

            choices = names(iris))



renderPlot({

  ggplot(iris, aes_string(input$x_axis, input$y_axis, colour = "Species")) +

      geom_point()

})

```

You need to call the data into your aes() block, not just the header name. When you call 'input$x_axis' it reads it as Sepal.Length, but does not pull the data in. I've included an example below:

renderPlot({

  library(tidyverse)

  data = iris %>%

    select(Species, input$x_axis, input$y_axis)



  ggplot(data, aes(x = data[,2], y = data[,3], colour = Species)) +

      geom_point()

})

Side note: I'd suggest you also clean up the dropdown lists so one cannot select two of the same and also cannot select Species..