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Comment by feoren

2 months ago

That's not how O(f(n)) notation works. You can't just plug in an n to O(f(n)) / O(g(n)) and claim a specific performance improvement. You have to actually know all the factors that are stripped off by big-O to do that, and you never really do. For instance, you're ignoring the cost to transform between domains.

> I know real world computation doesn't answer to the simple scaling equations ... but

No, no "but". This defeats the entire claim, and you can't just "but" it back.

Also, you appear to have used base-10 log for Log(3). It's almost certain that base-2 is more appropriate, leading to a factor of 1.8x, not 6x. But of course Log_1000(n) and Log_2(n) have the same Big-O, which is why the base is left off, so you really just cannot say anything specific at all. O(n^2) might be faster than O(n*log(n)) up to n = Graham's number.

>This defeats the entire claim, and you can't just "but" it back.

You may have missed what the "but" is doing- it's agreeing with you. My entire claim is defeated, and it uses the same reasoning that that the parent used to make their claim. I'm not attempting to show that there is an improvement, only that the lack of improvement has not been demonstrated by listing two Big-Os and setting n.

But yes, the log base 10 is my bad.