Histograms and error bars

[Mathieu Dubois]

Hi everyone,

I would like to plot an histogram to compare 5 experimental conditions.

For example let's say that I have 4 classes and 2 experimental conditions.
Therefore I have a 4*1 vector "classes" giving the classes and a 4*2
matrix "average" giving the average for each class and each experimental
conditions.
Then:
--> bar(classes, average)
does the trick.

The problem is that I want to plot error bars for each class and each
experimental condition.
I know how to do that with a single experimental condition with the
"errbar" function because in this case I know the x and y position of each
bar (x is given by "classes" and y by "average"). But with several
experimental conditions, each bar has a different x position. "bar"
internally compute this x position but I cannot access it so I cannot use
"errbar".

Does anyone have an idea?
Is there a way to "attach" errors to data and automatically plot them?

Thanks in advance,
Mathieu