Function.evaluate()

Hi

I'm working on a slice plane module. I've created a Gridded2DSet
and its points to extract the values from the input field. I got a tip a
while back that the method evaluate in Function could be used to
interpolate values. I could create RealTuples for 

The problem with this approach is that it requires massive object
generation. RealTuple objects are immutable, which means that each new
lookup would require a new RealTuple for each point.

In addition, I'm guessing that the Data object returned is a new one for
each method call. Also, casting back and forth costs a bit.

This approach is not very preferrable. I thought about implementing a
specialiced case for each set type, where I locate the cells the points
are in and interpolate manually, but it would require a separate
implementation for each set type, which in my opinion is not good design.

Any thoughts...

Thanks in advance

Gunnar