title: Set error bars to standard deviation on a ggplot2 bar graph
body: <p>I have a two-factor bar graph using ggplot2, where I used mean_se to add error bars with the standard error. I would like to use standard deviation instead of standard error. </p>
  
  <pre><code>library(tidyverse)
  
  #load diamonds dataset
  diamonds &lt;- diamonds
  
  #two-factor dynamite plot
  plt &lt;- ggplot(diamonds, aes(cut, price, fill = color)) +
  geom_bar(stat = "summary", fun.y = "mean", position = position_dodge(width = 
  0. 9)) +
  geom_errorbar(stat = "summary", fun.data = "mean_se", position = 
  position_dodge(width = 0.9)) +
  ylab("mean price") +
  ggtitle("Two-Factor Dynamite plot")
  
  plt
  </code></pre>
  
  <p>Is there a way to do this similar to using mean_se, but to generate error bars representing one standard deviation? mean_sdl doesn't seem to do this. Thank you.</p>