on 5/22/03 1:51 PM, Dar Scott at [EMAIL PROTECTED] wrote: > > On Thursday, May 22, 2003, at 11:32 AM, David Squance wrote: > >> -10*-10 is ambiguous, since you have two operations adjacent to each >> other >> (ultra picky, I know) >> Assuming *-10 is meant to be *(-10), -10*-10 = -(-100) = 100 > > I'm having trouble seeing an alternate meaning. > > Dar >
Here is the issue: Remember that numbers represented in computers are not represented in decimal form, but in a binary form. Negative numbers are not represented with a negative sign, but rather as a binary with a different first digit (1 instead of 0, I think). The algebraic order of operations is Parentheses, Exponent, Multiplication and Division (from left to right), and Addition and Subtraction (from left to right), or PEMDAS But algebraically, negation is a multiplication process. -5 = -1*5. So -10^2 means -1*10^2, or -100. Algebraically, the exponent only affects what it touches. That is why -10^2 means -1*10^2, and not (-10)^2. But since computers see numerical representation differently, the negation of a number is not a real "operation" to a computer. -10 is a single unit. So -10^2 in computer languages will always mean (-10)^2. Anti-intuitive? Yup. But if the engine were rewritten to check and correct for this algebraically, it would run a lot slower. Better for us just to recognize the difficulty and code around it. Raymond E. Griffith _______________________________________________ use-revolution mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/use-revolution
