>Hi all, > >I have what I hope is a trivial problem. I would like to >visualize some data on a regular grid. Unfortunately, the >coordinates of the grid notes are stored as follows: > >x0 x1 x2 x3 ... xn >y0 y1 y2 y3 ... yn >z0 z1 z2 z3 ... zn > >and I could not find in the documentation a way >to refer to this data from a dx file. > >Could anybody point me the right direction? > >Thanks in advance >Fabio Bettio
There is no trivial way to do it since you are (I think) calling for the full expansion of a 3D mesh of size (xn * yn * zn). DX is more literal and assumes normally that you are either providing the grid dimensions of a fully regular mesh or that you are providing all the explicit 3-vector position values you require. So for example if you declare the mesh as: origin 0 0 0 delta 1 0 0 delta 0 2 0 delta 0 0 1.5 counts 10 40 20 you'd have a nice 3D regular mesh (positions connected by cubic volumetric elements), starting at the origin, proceeding by 1 for each X item, 2 for each Y, and 1.5 for each Z. The mesh would have 10 * 40 * 20 positions (9 * 39 * 19 voxels). If you had the (X,Y,Z) values for all 8000 positions, that would be OK also. But what's not so easy is to create the object from a 10-vector of X values times a 40-vector of Ys times a 20-vector of Zs unless you do the following: Create a .dx file (a header file) that describes your data as follows. Let's assume for simplicity that you've separated the X values into their own file, Y into their own and Z into their own. You can certainly do this with them all together, but if the data is ASCII, you have to calculate the byte offset to the start of the Y and Z arrays in advance (a big pain). If the data file is binary, obviously this problem is a lot simpler. (left to the reader) object 1 class array type float rank 0 items 10 data file X.dat,0 object 2 class array type float rank 0 items 40 data file Y.dat,0 object 3 class array type float rank 0 items 20 data file Z.dat,0 object 4 class productarray term 1 # the 1 refers to object 1 previously defined term 2 term 3 object 5 class gridconnections counts 10 40 20 object 6 class field component "positions" value 4 # the productarray component "connections" value 5 # the gridconnections, topologically regular Chris Pelkie Vice President/Scientific Visualization Producer Conceptual Reality Presentations, Inc. 30 West Meadow Drive Ithaca, NY 14850 [EMAIL PROTECTED]
