[Flow-tools] chart an interface?

[David Faught]

I have a need to do a stacked chart of all NetFlow data exported from
a particular router that has a particular interface as either the
source or destination.  I don't care about any IP addresses or subnets
in this case, but the parts that get stacked have to be split by TOS.
I'm looking for a +in -out chart similar to FlowScan, but for a
specific router interface.  What's a good way to do this?

I'm currently using flow-tools, FlowScan with JKFlow, and FlowViewer.