On Feb 6, 2008, at 11:49 PM, Friedrich Foerster wrote:
> Daniel Russel wrote: >>>> The differences from the grid used in EMBed are: >>>> - The voxel index is actually a triple if ints. This makes >>>> computing >>>> a point in a voxel fast without the large tables used in EMBed. I >>>> think this is the right choice speed wise, but we can always test >>>> (and it is trivial to change). >>>> >>> The reason we had it as single array in EMBed is for consistency >>> with >>> external programs like fttw, EMAN. >>> I think that we should keep it like that. >>> >> It still has that. Just the index type is different. It also makes it >> easier to iterate over the whole thing. >> > just to add the reason for storing voxels in a 1d array rather than > 3d: > in image processing, all computations are typically done in loops, > i.e. > neighboring voxels are accessed in succession. therefore, it should be > faster in that case, and every program i know of (at least in the em > community) handles it this way. >> Its ok. The data is still stored in 1d, the voxel index is used only for iterating - and you can still just loop over the 1d array.