How to make dodge in geom_bar agree with dodge in geom_errorbar, geom_point

Question

I have a dataset where measurements are made for different groups at different days.

I want to have side by side bars representing the measurements at the different

Answer 1

This is an old question, but since i ran into the problem today, i want to add the following:

In

 geom_bar(position = position_dodge(width=0.9), stat = "identity") + 
   geom_errorbar( position = position_dodge(width=0.9), colour="black") 

the width-argument within position_dodge controls the dodging width of the things to dodge from each other. However, this produces whiskers as wide as the bars, which is possibly undesired. An additional width-argument outside the position_dodge controls the width of the whiskers (and bars):

 geom_bar(position = position_dodge(width=0.9), stat = "identity", width=0.7) + 
   geom_errorbar( position = position_dodge(width=0.9), colour="black", width=0.3)