#################
BurtW, maybe I'm too active here, if you dont like it, then you can ask me to leave and create a separate topic.
#################
No problem. We enjoy your informative posts and have used several of your ideas in our program.
Right now I am very busy with work and my daughter is very busy in school so we have not had time to work on the program.
We will get back to our version when things slow down a bit.
BTW we keep all our points in memory in a hash table also. Disk access is a no no, especially when we are targeting a GPU (eventually).