Arthur BesseFeb 22

Incredible stochastic algorithm, gets more reliable the larger your input, incredibly fast, trivial to implement and deterministic on its inputs

https://lemmy.ml/post/43537545

Show thread/home/pineapplelover
I’m confused, shouldn’t this be printing false no matter what the input is?
Feb 22 at 4:22pmWeb
Show threadfallaciousBasisFeb 22
You kind of suck at logic…
Show threadÆnimaFeb 22
You sound like my mom!
Show threadCarl [he/him]Feb 22
that’s the joke, since most numbers aren’t prime, this algorithm is technically highly accurate despite being completely useless.
Show threadantonFeb 22

The test suite probably looks something like this:

int tests_passed=0; int tests_failed=0; for(int i=0;i<100000;i++){ printf("test no. %d: ", i); if(is_prime(i)==actually_is_prime(i)){ printf("passed\n"); tests_passed++; }else{ printf("failed\n"); tests_failed++; } } //...
Show thread/home/pineappleloverFeb 23
Ah that makes more sense thanks. So the bottom one is a unit test and not the code being run itself
Show threadCouldbealeotardFeb 22

The output is not the output of the algorithm, it’s the output of the unit test.

95% of numbers up to that point at not prime. Testing the algorithm that only says “not prime” is therefore correct 95% of the time. The joke is that, similar to AI, the algorithm is being presented as a useful tool because it’s correct often but not always.