title: How I can change a value in a csv. using a slide bar in shiny?
body: <p>(and thanks in advance for your help)</p>
  <p>I'm trying to create a slidebar in my Shiny App. This bar has to be capable to change the value of % of chlorine in a modeling process. I mean that you initate your model with a fixed value that you can find in a csv. and then, the bar has to change this value, and of course, change the modeling results.</p>
  <p>I coded that for UI and SERVE:</p>
  <p>UI</p>
  <pre><code>            mainPanel(
                fluidRow(
                    column(12,
                        h3(&quot;Modificacio de Clor&quot;),    #title
                        p(&quot;Tria de percentatge per a modificar el Clor a la xarxa&quot;),  #subtitle
                        sliderInput(inputId = &quot;clor_modif&quot;, label = &quot;% Clor:&quot;, min = -1, max = 1, value = 
                                    0.75, step = 0.05, round = T), #sliderInput with relevant information of 
                                                                   #my bar 
                       )
                    )
                 )
              
      ),```
  
  ```shinyServer(function(input, output) {
  
  observe({
       #Database where the parameter of chlorine is saved
        simulation_parameters_zona &lt;- read.csv(&quot;./data/simulation_parameters_zona.csv&quot;, header = TRUE) 
       #The parameter is in 8th file
        simulation_parameters_zona &lt;- simulation_parameters_zona[8,]
       
       #I want the slidebar change the value and the value will be recorded in the csv. 
       #(simulation_parameters_zona). Because when we re-run the modeling, the shiny app takes into account 
       #the new value, and then changes de result of the model.
        
        val &lt;- input$clor_modif
        updateSliderInput(session, val, value = simulation_parameters_zona$dades2*val)
        
      })
  })```
  
  Actually, I tried several times how I could attach the bar to the file, but I can't... I'm sorry if the question is dumb (I'm sure about it). I'm a beginner with Shiny...
  
  
  
  
  ***Thank you very much for your help!***
  </code></pre>