带有coord_flip的ggplot2中errobar的自由缩放和位置

Question

Could this be related with coord_flip? I don't manage to get the free scale and the good position of errorbars with the following code:

ggplot(df, aes(x=d, y=value.mean, fill=s))+
  facet_grid(.~variable, 
             scales="free_y")+
  geom_bar(stat="identity", 
           position=position_dodge())+
  geom_errorbar(aes(ymin=value.mean-value.se, ymax=value.mean+value.se), 
                position=position_dodge(.9), 
                width=3)+
  scale_fill_manual(values=c("#7fc97f","#beaed4"))+
  scale_x_continuous(breaks=c(-60,-100))+
  coord_flip()+
  theme_bw()

Here is a sample of df:

s   d   variable    value.mean  value.se
f   -100    aa  315 48
g   -100    aa  394 73
f   -60 aa  284 48
g   -60 aa  293 82
f   -100    bb  60  6
g   -100    bb  55  7
f   -60 bb  116 14
g   -60 bb  123 21

Answer 1

To get good position of errorbars, one solution would be to convert to factor variable d and then position=position_dodge(0.9) will work

ggplot(df, aes(x=as.factor(d), y=value.mean, fill=s))+
      facet_grid(.~variable)+
      geom_bar(stat="identity", 
               position=position_dodge())+
      geom_errorbar(aes(ymin=value.mean-value.se, ymax=value.mean+value.se), 
                    position=position_dodge(width=0.9), 
                    width=0.3)+
      scale_fill_manual(values=c("#7fc97f","#beaed4"))+
      coord_flip()+
      theme_bw()

If you take d as numeric then you have to adjust width= of position_dodge() according to your data values. In this case it is 35 that positions errorbars as supposed.

ggplot(df, aes(x=d, y=value.mean, fill=s))+
      facet_grid(.~variable, 
                 scales="free_x")+
      geom_bar(stat="identity", 
               position=position_dodge())+
      geom_errorbar(aes(ymin=value.mean-value.se, ymax=value.mean+value.se), 
                    position=position_dodge(width=35), 
                    width=10)+
      scale_fill_manual(values=c("#7fc97f","#beaed4"))+
      scale_x_continuous(breaks=c(-60,-100))+
      coord_flip()+
      theme_bw()