title: Google Sheet Custom Function Not Recaculating
body: <p>Hi I have read about the caching issues with custom functions in Google Sheets, but I'm trying to understand why the following will successfully update if a cell is changed:</p>
  
  <pre><code>function doob(input){
   return input * 2;
  }
  </code></pre>
  
  <p>but this will not update:</p>
  
  <pre><code>function doob(input){
   var sheet = SpreadsheetApp.getActiveSpreadsheet();
   var range = sheet.getRange(input);
   var values = range.getValues();
   return values[0][0] * 2 ; 
  }
  </code></pre>
  
  <p>I need to get the range in order to use the .getBackgroundColor() of each cell.</p>