就是把 result window 清空（clear the result window）
是什么命令？应该怎么实现呢？
这个功能是比较有用的，有两点理由：
(1) after poking around awhile with a dataset and/or changing one's mind about an analysis, one wants to look at a fresh, clean set of results without seeing what came before (I won't comment on the psychology of this, but only admit that I occasionally feel this way myself), or
(2) one wants to print a clean analysis without previous mistakes and/or false starts. There may be other reasons, but off the top of my head I can't think of any.
哪位高手能够搞定？