This could be useful, but I tried it with some other numbers and it doesn't seem to perform very well. For instance, if you use your numbers and add an additional 10 "13"s to the end of the datalines string it still produces a very straight line. If you generate a random list of 100 numbers using rand('poisson',2) you can get a bunch of very non-straight lines, and only occasionally a nice straight line. If you generate a random list of 100 numbers using rand('poisson',10) you generally seem to get a straight line that starts curving upwards towards the higher end. I understand that 100 isn't a lot, but I would have hoped it would perform much better than the much shorter 13-heavy list, and especially with a mean of 2 you still get non-"poissonness" fairly frequently even with 1000 observations...