OpenEuphoria

Pattern Recognition

• Posted by Al Getz <xaxo at AOL.COM> Jan 16, 2001
• 378 views

Pattern detection is an interesting subject.
Its very hard to ask the question:

 "is there a function that will return 1 if my sequence contains a pattern
  and return 0 if it doesn't?"

because of at least the following reasons:

1. When you say "pattern" your not saying much at all about the data
   except that there be some sort of order present, and order is a
   very complicated criteria.  For example:

   A="tip"  --(reference string)
   B="atip" --clearly contains 'tip'
   C="pit"  --is this really 'tip' backwards?
   D="pti"  --is this really 'tip' with the p moved to the front of
              the word 'tip'?

   Some forms of "pattern recognition" will easily determine that B
   contains 'tip'.
   If you think that D (or C) is too far encrypted to be of any use, think
   again, because there are well known mathematical forms that will easily
   discover that C and D are simply phase shifted versions of A.

2. Normally when you try to recognize a pattern, you have other
   functions which attempt to compare other constraints to the data
   and determine if there is any validity to the outcome, even if
   these functions are "built in" when the code is written and appear
   transparent.  For the examples A,B,C and D above, if you were looking
   for only English language words then you could first compare entries
   to an expandable dictionary, and that would eliminate D, unless you
   included abbreviations, which might then include D.

Because of at least these two reasons, it would be a good idea to define
your problem a little more distinctly, or even specify the problem you are
trying to solve completely, if you intend to create a good algorithm.

Good luck with it,
Al