title: Boxplot schmoxplot: How to plot means and standard errors conditioned by a factor in R?
body: <p>We all love robust measures like medians and interquartile ranges, but lets face it, in many fields, boxplots almost never show up in published articles, while means and standard errors do so all the time.</p>
  
  <p>It's simple in lattice, ggplot2, etc to draw boxplots and the galleries are full of them. Is there an equally straightforward way to draw means and standard errors, conditioned by a categorical variable?</p>
  
  <p>I'm taking about plots like these:</p>
  
  <p><a href="http://freakonomics.blogs.nytimes.com/2008/07/30/how-big-is-your-halo-a-guest-post/" rel="noreferrer">http://freakonomics.blogs.nytimes.com/2008/07/30/how-big-is-your-halo-a-guest-post/</a></p>
  
  <p>Or what are called "means diamonds" in JMP (see Figure 3):</p>
  
  <p><a href="http://blogs.sas.com/jmp/index.php?/archives/127-What-Good-Are-Error-Bars.html" rel="noreferrer">http://blogs.sas.com/jmp/index.php?/archives/127-What-Good-Are-Error-Bars.html</a></p>