title: How to update a list in a for loop(cannot store ggplot object into the list)
body: <pre><code>plotss = list()
  for (i in 1:6){
    plotss[[i]] &lt;- qplot(x=total[,7], y= total[,names(total)[i]],geom = 'line')
  }
  </code></pre>
  
  <p>I found all the 6 components in the list plotss are actually the plotss[[6]], which means the i=6 totally replace the previous all 5 components. Can anyone please help with it? 
  Thanks a lot~</p>