So this has got me thinking. Apparently what I am calling Divide and Conquer is really called a binary sort. I have looked up on the interwebs to calculate the maximum number of iterations for a given number of values, but it seems that all the formulas offered up use functions for C. I am trying to figure out what a basic math formula for this is, given n values.
Bob S > On May 16, 2022, at 15:23 , Bob Sneidar via use-livecode > <use-livecode@lists.runrev.com> wrote: > > A maximum of 7 recursions are necessary to isolate a single instance of 100 > possible values. 1000 requires a maximum of 10. 10000 values requires 14. The > idea is that for every factor of 10, you need roughly 3 more recursions. This > of course assumes the data is sorted, which in your case is sorted into 3 > containers. If you know the limits of how many lines can be garbage, and how > many can be valid data, you narrow your scope significantly. > > Livecode is pretty damn quick at parsing this kind of data. If there are > consistent delimiters (in this case a line break) then even 20 or 30 > recursions is child's play. > > Bob S > > >> On May 16, 2022, at 15:00 , Bob Sneidar via use-livecode >> <use-livecode@lists.runrev.com> wrote: >> >> Do you know exactly which lines you need to toss, or do you need to searc >> the data to find out where the beginning and end of the useful data is? >> If the former, then just put line x to y of your data into a new variable. >> If the latter, then a divide and conquer approach might be the answer. Get >> the line 30% in, test for valid, get the line 40% in, test, then 35% then >> 32.5% or 37.5% depending on your test. >> >> You may only have to do this a dozen or so times to find the exact line >> where your valid data begins. >> >> The other way of course is to get it all into a SQL database (how did you >> all know I was going to say that??) The downside is that you have to iterate >> through all your data once. The upside is a good one liner query statement >> may be all you need to process your data. And if you need to make multiple >> passes at your data, all the better. >> >> Bob S >> >>> On May 16, 2022, at 10:46 , Rick Harrison via use-livecode >>> <use-livecode@lists.runrev.com> wrote: >>> >>> I have a large chunk of data that I want to >>> search as quickly as possible. >>> >>> Unfortunately the part I want to search is the >>> middle third of the data. The other thirds at >>> the beginning and at the end are just junk and >>> slow down my search so I want to get rid of them. >>> >>> I don’t want to search line by line as that >>> takes way too long. >>> >>> There’s no unique character dividing any >>> of these data regions. >>> >>> What’s the best way to do this? >>> >>> Thanks in advance! >>> >>> Rick >>> >>> >>> >>> _______________________________________________ >>> use-livecode mailing list >>> use-livecode@lists.runrev.com >>> Please visit this url to subscribe, unsubscribe and manage your >>> subscription preferences: >>> http://lists.runrev.com/mailman/listinfo/use-livecode >> >> _______________________________________________ >> use-livecode mailing list >> use-livecode@lists.runrev.com >> Please visit this url to subscribe, unsubscribe and manage your subscription >> preferences: >> http://lists.runrev.com/mailman/listinfo/use-livecode > > _______________________________________________ > use-livecode mailing list > use-livecode@lists.runrev.com > Please visit this url to subscribe, unsubscribe and manage your subscription > preferences: > http://lists.runrev.com/mailman/listinfo/use-livecode _______________________________________________ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
