Robin Haswell wrote: > I can think of lots of ways to do this but it's in a tight loop so I need > it to be as efficient as possible. Any help welcome :-)
There are 24 possibilities of having 4 numbers in a row, and the following 6 of them describe nonempty intervals (the remaining 18 are obtained by reversing the endpoints of one or both intervals, thereby making them empty): # separate a0 a1 b0 b1 b0 b1 a0 a1 # inside a0 b0 b1 a1 b0 a0 a1 b1 # cross a0 b0 a1 b1 b0 a0 b1 a1 The simplest is to exclude the first pair, i.e. not (a1<b0 or b1<a0) which simplifies to a1>=b0 and b1>=a0, given by Fredrik without proof ;-) You will have to decide whether you want ">" or ">=" (beware of the former when using floats). If you cannot assume that the pairs are in order, this will break. Ralf -- http://mail.python.org/mailman/listinfo/python-list
