Yes I am applying the inverse of the deltas to the x,y,z to get i,j,k, but slightly different than what you describe. I will take another look at the Regird module. It worked much too slowly before (actually never finished on larger data sets), but maybe I was not applying it correctly.
Jeff On Wed, 10 Jan 2001, Gregory D Abram wrote: > > 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 > > Please respond to [email protected] > > Sent by: [EMAIL PROTECTED] > > > To: [email protected] > cc: > 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 > > > > > > > ---------------------------------------------------------------------- Jeff Braun Geophysics Dept. mailto: [EMAIL PROTECTED] Montana Tech (406) 496-4206 1300 W. Park St. Butte, MT 59701
