Then I agree with Dave - this seems like a special case of Regrid, where
the grid is fully regular, nearest is 1 and radius is 0. I guess you are
inverting the 4x4 |d00 d01 d02 0| and applying the inverse to the scattered
(xyz) coordinate to get the (ijk) coordinate?
|d10 d11 d12 0|
|d20 d21 d22 0|
| ox oy oz 1|
I *hope* thats what Regrid does when the grid is regular, but then it
doesn't assume that the resulting (ijk) coordinate will hit the grid vertex
(or at least will with a little rounding).
Couldn't you get the cdep case in a macro in which you create a new grid
with 1 less point in each dimension and a new origin (orig. origin) + (0.5
0.5 0.5)(deltas), run Regrid as above, pull the resulting pdep data
component off the result, change the dependency attribute to "connections"
and Replace it onto the original grid?
This is exactly the sort of discussion we had in the modules committee
meetings.
Greg
Jeff Braun <[EMAIL PROTECTED]>@opendx.watson.ibm.com on 01/10/2001 01:46:07
PM
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Subject: Re: [opendx-dev] Adding a new module to CVS?
The user provides a grid, in the same manner as the Construct module with
origin, deltas, counts. The module simple goes through the scattered data
set and puts the data value on the closest grid point. If more than 2
points share a grid point then the average value is taken.
The module does not provide much benefit if there are much fewer scattered
points than number of grid points. But I have seen several data sets where
the number of scattered points is rather large, around the number of grid
points or more. In some case the scattered data points were actually
originally defined on a grid. Those people get frustrated with the time it
takes to run Regrid or Connect. This is just quick method of getting
scattered data onto a grid.
Jeff
On Wed, 10 Jan 2001, Gregory D Abram wrote:
>
> Sounds like a good idea.
>
> I guess I don't understand what the module does. Do you give it a grid
on
> which to place the data, or does it derive one?
>
> Greg
>
