On Sun, 04 Jun 2000 12:46:20 -0700, Xplo Eristotle wrote:
>Simen Kvaal wrote:
>> 
>> >A short history question: Was there a reason for using degrees with
>> >rotate and radians with the trigonometric functions, or did just
>> >happen that way?
>>
>> I'd say it's quite natural that the _functions_ take radians as
>> parameters, because in mathematics, you rarely use degrees to express
>> angles and/or to perform trigonometric oerations, to put it that way.

Actually, in school, we used degrees almost exclusively. Radians are
a lot more logical way to express an angle (there is a good reason that
a full circle has 2 pi radians, but there isn't any good reason it has
360 degrees) and it makes a lot of formulas simpler, but in geometry
people don't think in radians, but in degrees.

>> As for the rotations, the degrees is for many a more natural and
>> intuitive approach to orientation in space. You don't say "turn
>> around pi", but "turn around 180 degrees." Maybe it would be natural
>> to have alternate rotate-definitions, accepting radians?
>
>It would be more natural, IMO, to have trig that accepts degrees. When
>I was taking trig, we did plenty of work with degrees.. and in fact,
>since we specify angles in degrees pretty much everywhere BUT in a
>classroom - even my scientific calculator uses degrees by default - I
>don't see the point of using radians, which almost no one is familiar
>with.
>
>I don't WANT to rotate an object by 1/6th pi. I don't *NEED* to rotate
>an object by 1/6th pi. But it would be nice to ask for sin(30) and get
>.5 back.

I agree. Well, actually, I don't care much whether angles are specified
in degrees, radians, hours, or whatever, but I would like to have the
same unit everywhere.


>(In the spirit of offering a solution, how about a "trig_units" keyword
>in the global_settings, where a user could specify "degrees" or
>"radians"?)

Not good. That would break existing include files. A pragma which
affects only the source file it is in, but not any included files might
be safer, but I'm not too sure about that. The only way I can see which
wouldn't break compatibility would be a second set of functions (e.g.,
dsin, dcos, ...) which uses degrees instead of radians. 

Oh well, might as well leave it as it is, it's a minor nuisance. 

	hp


-- 
   _  | Peter J. Holzer    | Nicht an Tueren mangelt es,
|_|_) | Sysadmin WSR       | sondern an der Einrichtung (aka Content).
| |   | hjp### [at] wsracat      |    -- Ale### [at] univieacat
__/   | http://www.hjp.at/ |       zum Thema Portale in at.linux

Post a reply to this message