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by shagie 269 days ago
One of my early "this is neat" programs was a genetic algorithm in Pascal. You entered a bunch of digits and it "evolved" the same sequence of digits. It started out with 10 random numbers. Their fitness (lower was better) was the sum the difference. So if the target was "123456" and the test number was "214365", it had a fitness of 6. It took the top 5, and then mutated a random digit by a random +/- 1. It printed out each row with the full population. and so you could see it scrolling as it converged on the target number.

Looking back, I want to say it was probably the July, 1992 issue of Scientific American that inspired me to write that ( https://www.geos.ed.ac.uk/~mscgis/12-13/s1100074/Holland.pdf ) . And as that was '92, this might have been on a Mac rather than an Apple ][+... it was certainly in Pascal (my first class in C was in August '92) and I had access to both at the time (I don't think it was turbo pascal on a PC as this was a summer thing and I didn't have a IBM PC at home at the time). Alas, I remember more about the specifics of the program than I do about what desk I was sitting at.

1 comments

I wrote a whole project in pascal around that time. Analyzing two datasets. It was running out of memory the night before it was due, so I decided to have it run twice, once for each dataset.

That's when I learned a very important principal. "When something needs doing quickly, don't force artificial constraints on yourself"

I could have spent three days figuring out how to deal with the memory constraints. But instead I just cut the data in half and gave it two runs. The quick solution was the one that was needed. Kind of an important memory for me that I have thought about quite a bit in the last 30+ years.