Originally Posted by VerGreeneyes
Graeme: Are there any guidelines for how much memory colprof will end up using for the inverse lookup acceleration grid given the ARGYLL_REV_ACC_GRID_RES_MULT environment variable?
Not really. There are several bits that use memory, and it all interacts with the various settings.
The two main parts are the reverse lookup acceleration grid, and the calculation cache.
You can potentially increase the grid resolution but you will get to the point of diminishing returns, due to the computation time to set it up, and the fact that while it narrows down the inversion search, there will be a minimum number of cells that it will return.
The calculation cache helps when the inverted grid resolution is about the same or higher than the forward grid, since it avoids the heavy numerical work of inverting the forward cells interpolation when more than one query hits the same cell. The bigger the cache, the less chance that something will have to be recomputed, but there will be a point of diminishing returns.
What kind of range is worthwhile for that variable assuming memory isn't a concern?
If you want to figure it out, try different combinations of larger ARGYLL_REV_ACC_GRID_RES_MULT and ARGYLL_REV_CACHE_MULT in something like 30% increments (ie. 1.3, 1.7, 2.0). That would be 16 combinations in itself, but there is no point in going beyond the optimum for each individual value.Edited by gwgill - 8/31/13 at 1:17am