title: Horizontal standard error bars on bar graphs with negative values
body: <p>I have a bar graph that looks this:
  <img src="https://i.stack.imgur.com/jBMFA.png" alt="Horizontal Bar Graph"></p>
  
  <p>and I am trying to get standard error bars on it - so two standard error bars for each column (one for the positive Y, and one for the negative N). I am aware of geom_errorh, but I cannot get it to work for this type of bar graph. 
  Here is a reproducible example with the code that I used to get a bar chart like the one above:</p>
  
  <h1>Dataframe</h1>
  
  <pre><code>Behavior&lt;-as.character(c("Hammock","Hammock","Climbing Trees","Climbing Trees","Structures","Structures","Grade","Grade"))
  Presence&lt;-c("Y","N","Y","N","Y","N","Y","N")
  Mean&lt;-as.numeric(c("18.5", "-6.4","3.5","-6.8","13.2","-10.1","4.7","-2.3"))
  SD&lt;-as.numeric(c("17.6","-11.9","1.2","-4.4","3.6","-6.25","1.23","-0.4"))
  DF&lt;-data.frame(Behavior,Presence,Mean,SD)
  </code></pre>
  
  <h1>Coord Flip Geom Bar</h1>
  
  <pre><code>brks &lt;- seq(-20, 20, 2)
  lbls = paste0(as.character(c(seq(-20, 0, 2), seq(2, 20, 2))), "")
  
  
  
  ggplot(DF, aes(x = Behavior, y = Mean, fill = Presence )) + 
        geom_bar(data = subset(DF, Presence == "N"), stat = "identity") +
        geom_bar(data = subset(DF, Presence == "Y"), stat = "identity") +
        scale_y_continuous(breaks = brks,labels = lbls) + 
        scale_fill_manual(values=c("#0b6bb6", "#6eaf46"),name="", breaks=c("N", "Y"),labels=c("N", "Y"))+
        coord_flip()+  
        theme_bw()+
        xlab("Pen Characteristic - Behavior")+
        ylab("Average Behavior per Session")+
  </code></pre>
  
  <p>Is it possible to get the SE bars on this type of graph?</p>
  
  <p>Thanks!</p>