Suppose I have the following simplified distribution: time | value 1 | 2 2 | 4 3 | 8 4 | 16 1 | 1 2 | 3 3 | 9 4 | 27 1 | 40 2 | 20 3 | 10 4 | 5 1 | 12 2 | 1 3 | 99 4 | 23423 These are all part of the same dataset (so one x can have multiple values here, eg. time = 1 corresponds with value = 2,1,40,12). I separated them because the first 3 have an obvious pattern within their slope (2, 3 and 0.5) and the last does not have a pattern in its slope. Time is in days, and the values represent a quantity. Now, how do I use SPSS to find the elements of a distribution that together form a pattern (any kind of pattern) in their slope? And how can I make it also include elements that almost follow this pattern, but have slight variations (a variation that I can set)? Any feedback is appreciated. Thanks. **Update:** It looks like SPSS is not the best tool for the task. I am interested in the R language however. If anyone could recommend any books regarding this field of pattern recognition in R, that would be great.