Re: Saving VisAD Data objects

• To: Steve Emmerson <steve@xxxxxxxxxxxxxxxx>
• Subject: Re: Saving VisAD Data objects
• From: Dave Glowacki <dglo@xxxxxxxxxxxxx>
• Date: Thu, 12 Mar 1998 18:45:39 -0600

> > I'm assuming that I want to use DataVisitor to suss out exactly what
> > the Data object holds.  Is this correct?
> 
> Maybe not.  
...
> Take a look at visad.data.netcdf.DataAdapter
...
> The end result is that I'm using the Builder design pattern rather than
> the Visitor design pattern.

I'll check this out tomorrow.

> I'm not sure.  Thinking about VisAD data objects as arrays might be too
> limiting.  For example, VisAD Fields can be arbitrarily nested:
> 
>     time -> (y -> (x -> z) )

This could be thought of as a 4-dimensional array...

> My solution was to define an object that knows how to access the VisAD
> data at each level and then to link them together from the innermost
> level to the outermost level.  See visad.data.netcdf.*Accessor.  Once
> I've reach a leaf node of the VisAD data object, I then define a netCDF
> variable that uses the chain of DataAccessors to access the data values.

This won't necessarily work for me; FITS objects can't really be that
complicated.  The "time -> (y -> (x -> z))" example would probably need
to be written as either a bunch of 3-dimensional images or an even larger
bunch of 2-dimensional images.

• Follow-Ups:
  • Re: Saving VisAD Data objects
    • From: Steve Emmerson