Re: Re: Modulus Inconsistencies (Or Calling all Mathematicians)

In math, we get to make up anything we want, and then reason from it. If you don't believe me, you just haven't studied enough higher math. What is important is whether it is consistent and useful.

Well, I did study higher maths. And your argumentation is basically right. For example, if you ask how much is 2+2? one should reply it depends. Why? Because you ain't saying anything about the base on which respect you are calculating the result (e.g., 2+2=0 in the weird ~~4-based~~ Z(4) numerical system -the integers modulo 4).

But we ain't talking about higher mathematics here, that's plain algebra in the old ~~10-based numerical system~~ Z, the dear old integer mathematics we studied in the early years of the school, where my teacher used to hit me on my face if I wrote a negative reminder (or one that was too big). And in dear old mathematics the modulus is always positive.

Ciao!
--bronto

Update: thanks to Enlil for pointing errors around; fixed (hopefully :-)

The very nature of Perl to be like natural language--inconsistant and full of dwim and special cases--makes it impossible to know it all without simply memorizing the documentation (which is not complete or totally correct anyway).
--John M. Dlugosz

Comment on Re: Re: Modulus Inconsistencies (Or Calling all Mathematicians)

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Re: Sadistic grammar school teachers by no_slogan (Deacon) on Mar 26, 2003 at 18:37 UTC
But we ain't talking about higher mathematics here, that's plain algebra in the old 10-based numerical system, the dear old mathematics we studied in the early years... No, actually we're not talking about that. We're talking about programming, so we're talking about what computers do. And what most of them do nowadays is implement a single instruction that does a truncating divide and gives you a quotient and remainder from that operation. Some extended-precision arithmetic packages (like GMP) give you both round-towards-zero and round-towards-negative-infinity (in other words, positive remainder) division routines, but that's as maybe.	[reply]

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Re: Sadistic grammar school teachers
by no_slogan (Deacon) on Mar 26, 2003 at 18:37 UTC

But we ain't talking about higher mathematics here, that's plain algebra in the old 10-based numerical system, the dear old mathematics we studied in the early years...

No, actually we're not talking about that. We're talking about programming, so we're talking about what computers do. And what most of them do nowadays is implement a single instruction that does a truncating divide and gives you a quotient and remainder from that operation. Some extended-precision arithmetic packages (like GMP) give you both round-towards-zero and round-towards-negative-infinity (in other words, positive remainder) division routines, but that's as maybe.

[reply]