title: ggplot2: plotting error bars for groups without overlap
body: <p>I wish to show the effect of two pollutants on the same outcome and was happy with the plot when there are no groups. Now when I want to plot the same data for all-year and stratified by season, I either get overlaps of error bars or three separate panels which are not optimal for my need.<br>
  Sample data could be accessed from here: 
  <a href="https://drive.google.com/file/d/0B_4NdfcEvU7LV2RrMjVyUmpoSDg/edit?usp=sharing" rel="nofollow noreferrer">https://drive.google.com/file/d/0B_4NdfcEvU7LV2RrMjVyUmpoSDg/edit?usp=sharing</a></p>
  
  <p>As an example with the following code I create a plot for all-year:</p>
  
  <pre><code>ally&lt;-subset(df, seas=="allyear")
  ggplot(ally,aes(x = set, y = pinc,ymin = lcinc, ymax =ucinc,color=pair,shape=pair)) +
  geom_point(position=position_dodge(width=0.5) ,size = 2.5) + 
  geom_linerange(position=position_dodge(width=0.5), size =0.5) +  theme_bw() +
  geom_hline(aes(yintercept = 0))  + 
  labs(colour="Pollutant", shape="Pollutant", y="Percent Increase", x="") + 
  scale_x_discrete(labels=c(NO2=expression(NO[2]), 
                                 NOx=expression(NO[x]), 
                                 Coarse= expression(Coarse),
                                 PM25=expression(PM[2.5]),
                                 PM10=expression(PM[10])))  + 
  theme(plot.title = element_text(size = 12,face="bold" )) + 
  theme(axis.title=element_text(size="12") ,axis.text=element_text(size=12)) 
  </code></pre>
  
  <p>But when I add facet_grid(. ~ seas) I will have three separate panels. How can I display this data for all year and divided by seasons in one panel? </p>