To select subset what I did is to use the Include module which leaves out unwanted positions/elements.
The order is - mark "positions" - compute (using Compute) from these positions the ones which are inside the domain. I use a boolean expression which returns 1 if the point (a) is in the domain given by vectors p1 and p2: ((a.x > p1.x) && (a.y > p1.y) && (a.z > p1.z) && (a.x < p2.x) && (a.y < p2.y) && (a.z < p2.z) ) The vectors p1 and p2 come from Vector interactors in my case. Input 'a' is the output from the Mark module. - use the resulting 1 or 0 to include points using the Include module (use cull to actually reduce the size) - Unmark to restore the original data. Gib Bogle wrote >I have a big image (a surface) that I want to extract a piece of. Because I >am zooming in I need to >increase the grid resolution to avoid the >jaggies. Clipbox allows me to select the subregion, but since it does not >reduce the memory >requirements I still run out of memory when I try >to refine the grid. Is there any way to select a subregion (e.g. a rectangle) >that also reduces the >memory requirements? The only other way I >can think of to do what I want to do would be to edit the input datafiles. >One of these is easy to >handle since I create it, the other is a TIFF >file. Which raises a second question: can someone suggest a good public >domain TIFF editor that I >could use to extract a specified >rectangle? --
