consider binary search in simplify.R

[shawnlaffan]

The while loop in simplify.R takes a long time with large data sets. It seems to iterate from one end of the list to close to the minimum threshold.

rmaxent/R/simplify.R

Line 162 in 08d1103

while(min(pct) < pct_thr && length(pct) > k_thr) {

I don't entirely follow the code at the moment but if min(pct) always decreases monotonically then one can use a binary search to reduce the number of calculations. This will work in O(log n) time instead of O(n), on average.