using matplotlib to plot running totals

Hello,
I have a table that contains a series of values for each day
I would like to use matplotlib to plot the running total of those
values over time
right now, I am computing an intermediary "running total table" myself
and then plot that.
I just wonder whether matplotlib can be instructed to plot running
totals so I can skip that intermediary step
thanks for any insight you might have
-frank