instead of fix repulisve gap, I decided to use a factor larger than 1 so that some place near a droplet wouldn't have nucleation. this is more physical
If the aspect ratio (asp) is not 1, the position and size of droplets cannot be precisely presented on screen
save data to file
Find a bug for bfobj[[as.character(big)]]&deat.t<<-t+dtp;

initially, I used '<-' so that change cannot be made in global environment
some testing function