Creating a subsampling set

Hello, everyone,

Apologies is this query demonstrates my ignorance, but . . .

I have a FieldImpl containing a 3-D data set. The domain set is a Gridded3DDataSet, created for a sample grid which was nx x ny x nz points, with a manifold dimension of 1 (e.g., the data set represents temperatures on an irregular grid of lat-lon-pressure).

So far, so good: I can create my data set nicely, and write it out as a VisAD file. But now I would like to read it back in, then make arbitrary 2D displays of pressure surfaces, interpolating, or not, as appropriate.

The way to proceed would appear to be to

1) make a sampling set of the desired slice, namely, a set with all the lat-lon points of the original data set, and an arbitrary setting of the pressure level 2) create a new flatfield by resampling my original data set to this sampling set
3) and plot the result the way I would any other 2D data set.

(f there's a better way please let me know).

However, I run into trouble on (1). I can certainly get the sampling set back out of the FieldImpl, and I can get the samples array out of the sampling set, but how can I get the original dimensions of the set (nx x ny x nz)? There appears to be a private member (lengths[]) of Gridded3DSet which would contain the information I need, but there are no accessors for it.

I can't be the first person to encounter this, so I suspect I'm missing something fairly basic. Any suggestions?

        Edward