title: Indicating the statistically significant difference in bar graph USING R
body: <p>This is a repeat of a question originally asked here: <a href="https://stackoverflow.com/questions/11517986/indicating-the-statistically-significant-difference-in-bar-graph">Indicating the statistically significant difference in bar graph</a> but asked for R instead of python.</p>
  
  <p>My question is very simple. I want to produce barplots in R, using ggplot2 if possible, with an indication of significant difference between the different bars, e.g. produce something like this. I have had a search around but can't find another question asking exactly the same thing.</p>
  
  <p><img src="https://i.stack.imgur.com/3I6El.jpg" alt="bar plot showing error bars and sig. diff marking beween bars"></p>