rotating and moving 2D

[rpgfan3233]

http://mathforum.org/library/drmath/view/55451.html might be a good start. http://en.wikipedia.org/wiki/Gon - the Wikipage for it

[phycowelder]

LOL
ok that explains a lot!

Some people mess with what souldnt be messed with!

[rpgfan3233]

Yeah, and I think mils (6400 mils = 360 degrees) are used a bit more than grads/gradians/gons.

Additional calculations:
DEG -> MIL: numDegrees * (160 / 9)

RAD -> MIL: numRadians * (3200 / PI)

GRA -> MIL: numGrads * 16

MIL -> DEG: numMils * (9 / 160)
MIL -> RAD: numMils * (PI / 3200)
MIL -> GRA: numMils * (1 /16)

Regarding the GRA<->MIL conversions, anyone like hexadecimal (base 16)? :lol:

Edit: Here's something fun to play with: http://www.1728.com/angles.htm?b0=180

[Sisophon2001]

Hi:

I have used some survey instruments calibrated in gradians, and they were Soviet made, not French. It is actually very convenient for field work to think of every quarter turn as 100, and a full turn as 400. You always know where you are pointing the instrument in your mind, even if you are looking at a tiny view field.

90, 180, 270 and 360 are less intuitive measurements. When you see 285 on a dial in a theodolite, which way are you facing? When using gradians, then 316 tells you are 16 gradians past the 3/4 mark.

You are always using computers to analyze the data anyway, so it does not care which measurements you use. It is the intuitive feel for data that is most important.

It is possible to make progress on things like driving on the right side of the road, and using the metric system of measurement. But how may people actually use survey instruments, or even know what a gradian is? I am not holding my breath for a change.

Garvan

[Deleter]

a simple way of understanding radians:
if, given any circle, you wrap a radius around the circumfrence, the resulting angle caused by that arc is whats defined as a radian.

We know a circumfrence of a circle = 2 * pi * r; from these you can see that there must be 2 pi radians in a circle.

A good way to think of conversions is this:
2 pi radians = one circle so to find the PERCENTAGE of a circle covered by a given number of radians would be
(radians / 2* pi)

With degrees, the same would be
degrees/360.

Now both are in percentage of a circle. From these, you can see that:

radians / 2pi = degrees/360

Multiply both sides by 2:

radians/pi = degrees/180

Now the final solution:

For Radians:
radians = degrees * pi / 180

For degrees:
degrees = 180 * radians / pi

Well that wasn't as easy at it seemed in my head....hopefully at least how i got the conversions makes sense given the percentage of a circle thing.