title: How to plot selected input from selectInput() function in shiny?
body: <p>I am using the following two Input functions code in shiny:</p>
  
  <pre><code>selectInput("categoryVisu", label="SELECT CATEGORY", choices = list("Full" = "full", "Fact" = "fact", "Fact Positive" = "factpos", selected = "full", multiple = TRUE)
  </code></pre>
  
  <p>and</p>
  
  <pre><code>selectInput("investerVisu", label="SELECT INVESTOR", choices = list("Informed" = "inf", "Noise" = "noise"), selected = "inf", multiple = TRUE)
  </code></pre>
  
  <p>My task is now, if the user select for example "Full" and "Informed" than my code should take the column "InformedFull" from my dataset to print the code. How can I handle this? My DataSet looks like this:</p>
  
  <p><a href="https://i.stack.imgur.com/fOBCf.png" rel="nofollow noreferrer">Dataset</a></p>
  
  <p>I already did the ggplot code, that looks like this:</p>
  
  <pre><code>ggplot(data = OLS.Data, aes(x=OLS.Data$Date, y=...))+geom_line()
  </code></pre>
  
  <p>So where I placed the ... their should be based on the booth selection of my selectInput, be the correct column of my dataset. </p>
  
  <p>My UI Boxes looking like this:</p>
  
  <pre><code>  tabItem(tabName = "visu",
            fluidRow(
              box(
                title = "Controls-1", 
                status = "primary", 
                solidHeader = TRUE,
                width = 3,
                selectInput("categoryVisu", label="SELECT CATEGORY", choices = list("Full" = "Full", "Fact" = "Fact", "Fact Positive" = "Fact.Pos", "Fact Negative" = "Fact.Neg", "Emotions" = "Emotions", "Emotions Fact" = "EmotionsFact"), selected = "Full", multiple = TRUE)
              ),
  
              box(
                title = "Controls-2", 
                status = "primary", 
                solidHeader = TRUE,
                width = 3,
                selectInput("investerVisu", label="SELECT INVESTOR", choices = list("Informed" = "Informed", "Noise" = "Noise"), selected = "Informed", multiple = TRUE)
              ),
  </code></pre>
  
  <p>And my server file:</p>
  
  <pre><code>server &lt;- function(input, output) {
  
    observeEvent(input$categoryVisu,{
  
      partA&lt;-input$catagoryVisu
      partA&lt;-as.character(partA)    
  
    })
  
    observeEvent(input$investerVisu,{
  
      partB&lt;-input$investerVisu
      partB&lt;-as.character(partB)
  
    })
  
    partC&lt;-paste(partB,partA)
  
    DataFus&lt;-OLS.Data$partC
  
    output$myPlot &lt;- renderPlot({
      ggplot(data = OLS.Data, aes(x=OLS.Data$Date, y=OLS.Data$NYSE))+geom_line()+geom_line(data = OLS.Data,aes(x=OLS.Data$Date, y=DataFus),color="red")+geom_line(alpha = input$alphaVisu)
    })
  
  }
  </code></pre>