ah, sorry, I was responding to the wrong line, I thought you were asking about the `add_collections` line and was very confused.

I don't know about the `update_datalim` line.  My assumption was that the corners it picks out are not the same as the data limits `add_collections` would produce, but I didn't do any testing of that assumption.

I am defending at the beginning of December so I don't want to commit to too much extra stuff at this point.  

I think the plan is to kick finance.py out of matplotlib into it's own project in a near future (1.5?) release.