Betsy: Chris indicated how you could use Construct as I implied in my earlier e-mail in order to get things regular. I'm sorry that I didn't give the explicit details. (Thanks, Chris.)
What Chris suggests is useful for atmospheric models or other gridded data where you may be topologically regular, but geometrically regular in only 1 or 2 dimensions. The easiest way to do this is at Import time. It can be done with the native format but there are also conventions described in the user's guide for doing it with general array and netCDF import. There are some convoluted ways to do this in the VPE... Chris Pelkie <[EMAIL PROTECTED]>@opendx.watson.ibm.com on 08/23/2000 11:50:34 AM Please respond to [email protected] Sent by: [EMAIL PROTECTED] To: [email protected] cc: Subject: Re: [opendx-users] why is data irregular? >Lloyd, > >Thanks for the reply. > >The situation I described (using Compute to shift the Z position) was just a >sample test case. >I'm trying to use your ConvertToCellCentered macro on my data which is >regular in x and y, but delta z varies. You had suggested in an earlier >e-mail that I use Slice to create a set of horizontal slices as a series >group. Then do a ForEachMember loop for each member of the series and use the >macro and accumulate the results in a new series. Then, use Stack to recreate >the volume. > >However, DX doesn't think the slices are regular so ConvertToCellCentered >doesn't work. I have imported the data from a netCDF file and do not alter >the data at all before I create the series of Slices. > >Am I just out of luck on this, or do you have any suggestions. > >Thanks...Betsy If you say your data is regular in XY but DX thinks it is not, you can use Inquire to find out the value of X and of Y (check Inquire's contextual Help for the syntax, "grid counts", I think). Use this as input to Construct to manufacture a generic grid of XxY. Then Replace your data array (and any other dependent arrays, using more than one Replace in serial) onto this grid. NOW, DX will think your XY slice is regular and you can make the series and Stack. BTW, you can also investigate making a semi-regular grid using "product array" but this can only be done by defining a DX input file, not within the DX visual programming environment to the best of my knowledge. This is more advanced but might be useful sometime. I've done this for USGS since both their X and Y and Z were "irregular" but the stacked set was conceptually "regular" topologically (just not position-wise). So we multiply a vector of X positions by a vector of Y positions to make a semi-regular XY mesh, then by Z to make a semi-regular volume mesh (this is done in a .dx file then imported). Given a separately imported fully regular data array of size XxYxZ, one can then simply Replace the data onto this mesh. Chris Pelkie Vice President/Scientific Visualization Producer Conceptual Reality Presentations, Inc. 30 West Meadow Drive Ithaca, NY 14850 [EMAIL PROTECTED] (607) 257-8335 or (607) 254-8794
