Re: Combining animations in spreadsheet

Hi John,

> I have data with a MathType like:
> 
> (Time -> ((lat, lon) -> value))
> 
> I would like to be able to do a combine on multiple cells like this in
> order to produce animations.  When I do so I get the error:
> 
> could not evaluate function "combine"
> 
> Is there any way to make this work?
> 
> MORE DETAIL:
> I am working on an educational application that uses the VisAD
> spreadsheet.  What I would like to be able to do is have many cells of
> data at different time periods and allow students to assemble their own
> animations.  The data files I import to VisAD are serialized VisAD
> objects.  Each one has a Linear1DSet consisting of 1 element associated
> with time.  The spatial data are mapped using a Linear2DSet.

It may be difficult to do this in the SpreadSheet, but the
API gives you a number of ways to program it in a "custom"
spread sheet.  Basically, create a new FieldImpl with the
same MathType as your files, but whose domain Set is a
Gridded1DSet with as many time steps as you have altoghether
(it can be a Linear1DSet if the times are evenly spaced).
Then do something like:

  for (int i=0; i<ntimes; i++) {
    FlatField time_step = field[i].getSample(0);
    new_field.setSample(i, time_step);
  }

That is, take the single time step Filed from each file
and merge them into the new FieldImpl.

Cheers,
Bill
----------------------------------------------------------
Bill Hibbard, SSEC, 1225 W. Dayton St., Madison, WI  53706
hibbard@xxxxxxxxxxxxxxxxx  608-263-4427  fax: 608-263-6738
http://www.ssec.wisc.edu/~billh/vis.html