RE: null scalary type in ScalarMap

Hi Michelle,

> I'm actually trying to have null values for just the DisplayRealType and
> not the ScalarType. I want the possibility for an input field to be
> mapped to a null value as one possible visualization instead of *always*
> mapping every single input field in the data set to a VisAD parameter.

If you don't want any ScalarMap for a ScalarType, just don't
construct any ScalarMap for that ScalarType. This is really a
user interface issue. Note that the mapping dialog window in
the SpreadSheet doesn't require the user to define ScalarMaps
for every ScalarType occuring in the Data.

> However, as I dig further and further into the original code, I'm
> finding that I would have to modify many classes to avoid null pointer
> exceptions. Am I correct that there would be no simple way to wrap a
> null DisplayRealType without getting null pointer exceptions?

That is correct. I often fantsize about a car that has pogo
sticks in place of wheels (I do), but would expect complexities
if I actually tried to modify my car that way.