Runway ID

On Mon, 17 Oct 2005 03:18:03 GMT, Jose
wrote:

This is correct rounding, but it is it what George stated. He stated
"round 1/2 to the EVEN number.", which would imply .245 - .26 which is
not true. What =is= true is
.245 - .25
.255 - .26
.265 - .27

This is not "rounding 1/2 to the even number".

Jose, you are with the majority, and you are with what it being taught
in today's schools until higher level mathematics.

The round (exactly) half to the even is correct.

0.2449 - 0.245 - 0.24 - 0.2 but the 0.24 is not for this rule,
rather because the full precision number was under 0.5

0.3499 - 0.350 - 0.35 - 0.3 but again, rule isn't applicable
0.3501 - 0.350 - 0.35 - 0.4 but rule isn't applicable

you have to round from the full precision to the final value in 1
step; the sequential above is interesting, but not as it is done for
the reasons obvious above.

0.5 (exactly) - 0.
1.5 (exactly) - 2.
2.5 (exactly) - 2.
3.5 (again, exactly) - 4

or, fwiw, 1234.5 - 1234. and 1235.5 - 1236.

It used to be taught that way in elementary school, but was changed
between when I went to school (1950s) and when my children went to
school (1990s).

My son has a math degree, and remarked about how higher level high
school and college profs complained about having to correct the
elementaty and middle teachers teaching, but that they taught what
they were given, so it wasn't their fault.

0.5 (exactly) - 0.
1.5 (exactly) - 2.
2.5 (exactly) - 2.
3.5 (again, exactly) - 4

No.

0.5 (exactly) - 1.
1.5 (exactly) - 2.
2.5 (exactly) - 3.
3.5 (again, exactly) - 4.

Do you have a printed reference for what you espouse above?

Jose
--
Money: what you need when you run out of brains.
for Email, make the obvious change in the address.

"GeorgeB" wrote in message
...
Jose, you are with the majority, and you are with what it being taught
in today's schools until higher level mathematics.

The round (exactly) half to the even is correct.

George, you're right that rounding is often performed as you say (i.e.,
exactly half rounds to the nearest even integer), for the reason you say (to
avoid statistical biasing). But I'd quibble about calling that "the" correct
way. The function round(x) can be defined in various standard ways, and
different ways can be more useful for different purposes, but there's no
sense in which one conventional definition is the unique correct one.

http://mathworld.wolfram.com/Nearest...rFunction.html

--Gary

On Mon, 17 Oct 2005 11:03:57 -0400, "Gary Drescher"
wrote:

"GeorgeB" wrote in message
.. .
Jose, you are with the majority, and you are with what it being taught
in today's schools until higher level mathematics.

The round (exactly) half to the even is correct.

George, you're right that rounding is often performed as you say (i.e.,
exactly half rounds to the nearest even integer), for the reason you say (to
avoid statistical biasing). But I'd quibble about calling that "the" correct
way. The function round(x) can be defined in various standard ways, and
different ways can be more useful for different purposes, but there's no
sense in which one conventional definition is the unique correct one.

http://mathworld.wolfram.com/Nearest...rFunction.html

That, and Mathematica, were what I was going to reference; however,
you are correct that I had my head up that smelly place to consider it
to be "the" correct way. I've it even further up that smelly place to
get off on this when the question was on naming runways based on their
magnetic heading ... which is not a constant thing in the short or
long term, so what to do with a 5 is absolutely not going to be based
on EXACTLY anything.

Thanks for saying it so well.

George