Ok, "invalid positions" will separate the boundary points from the
volume points but in respect to the boundary conditions the boundary
points are not equivalent. Is it possible to mark the boundary points
with a tag/property that specify the type of boundary conditions
imposed on the surface this point belongs?
Thanks for your comments,
Ted
Sure, just create multiple different components each carrying a
particular type of tag/property and attached in a one-to-one
correspondence to each and every position (including interior
positions because you have to retain the same structure for each
component attached to a field).
Of course, the interior points don't have a tag, so make it either a
bogus number like -99 or something to preserve the presumed numeric
nature of the tag elements. If they are strings, then use "NA" or
something. The invalid positions knock these out anyway when you go
to display the tags (so only the boundary tags show up). That's why I
proposed invalids.
So you have something like:
x, y, z, data1, data2, tag1, tag2, invalid
tuple for each and every point in the data set.
data1, data2,... are the various data values you measured (temp,
pressure, etc.) and can be scalar or vector as desired. tag1, tag2,
.... are various properties. Each column must have consistent type,
but as mentioned, tag1 could be numeric and tag2 string. invalid is
the invalid marker already discussed.
If you think of the positions as the base array that "carries" all
the other components, then imagine laying a sheet of data over these
positions. This sheet must have a data entry to correspond with every
position (position-dependent data). Then, the invalids sheet also has
a value for every position, but the way DX utilizes this sheet is to
knock holes out where invalids are 01. This takes out the underlying
position and all associated data/tags/etc with that position, either
permanently (if you cull) or temporarily (treating it as a 'bandpass'
filter if you like).
If David's book doesn't answer all your questions, my company does do
DX consulting for agencies like yours. (:-)
Chris Pelkie
Vice President/Scientific Visualization Producer
Conceptual Reality Presentations, Inc.
30 West Meadow Drive
Ithaca, NY 14850
[EMAIL PROTECTED]
