> Yeah, that's something that could be a project in itself. There are a few 
> ways to do
> tables that I know of. JSBSim does "gridded" tables up to three independent 
> variables. I'd
> like to extend that to ungridded tables of "n" dimensions. Maybe there's an 
> algorithm
> around somewhere for that. I know where to look for at least one.

It's nice to be able to have backout routines for interpolation
tables, as well, which can be extremely helpful in initialization
code.  For tables up to 3d with fixed independent indices (is this
what you meant by 'grid', or did you mean fixed intervals?), this is
pretty straightforward.  Creating backout utilities for larger
dimensions and varying indices can be difficult.

Also, if you've got more than 3 inputs to a lookup table, you've
probably not done enough data reduction, and you're asking for
headaches when tuning the model.  Usually, you can uncouple the
dependencies enough to avoid such a mess, using multiple, smaller


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