So yes, that is what I have been using, when the R script returns something back and it needs to be displayed (an image in my case).

Here I don't have anything returned (except may be for a status code) and also I DO NOT have any 'myDiv' element to render to, but seems like renderTo is a required part of a WebPart, cannot have a declaration/definition without it, is that right? Should I then have a dummy/empty div in this case?
How do I suppress any kind of output from R script to not get back to the JS, so that nothing gets really rendered to that div?

What is the param "showSection"? What kind of values can it take up?

Thanks.