Atan2

[T. D. W.]

Simpe question, what does Atan2 mean?

native Atan2 takes real y, real x returns real

 

[Binsu]

Might help you maybe with the question at hand: Atan2 Questions and Usage of Atan2

 

[chobibo]

Arc Tangent, I think, it's considers the quadrant for the angle. Here's the wikipedia link, that's more detailed.

EDIT: I lol'd, Flame Phoenix haha xD good times those where...

 

[T. D. W.]

Arc Tangent seems it...
thx for both

 

[Cokemonkey11]

The tangent function in trigonometry is used to calculate the ratio of a right triangle's opposite leg to its adjacent leg, given the central angle of the right triangle.

Likewise, the ARC tangent function is used to calculate the central angle of a right triangle given the ratio of the triangle's opposite leg to its adjacent leg.

From this you should see that tangent and arctangent are inverses of one another - in fact, Atan is often written in math like Tan^-1 (they are synonymous)

Hence, Atan(y/x) results in the angle of a right triangle with central angle at the origin, right angle on the x axis, height y, and width x.

The only issue with this is the fact that if y or x are negative (or both are negative), the value given to Atan can be misinterpreted, and so although the angle is correct, its phase might not be the desired value!

Atan2 to the rescue. Atan2 accepts the y and x values as separate parameters, and so returns a value on [0,2pi] - extremely useful for scripters working in space.

For an example, take a look at the definition of AngleBetweenPoints() included in blizzard.j (JNGP has a function list that can display it)

 

[T. D. W.]

Dam it, so it's CoTan... "French Math" play that sums it up all
Thanks !

 

[Cokemonkey11]

I don't know about French, but in english, Cotangent is something different! Cot(x/y) = Tan(y/x) - not the same as arctan!

 

[T. D. W.]

Solved

 

[Cokemonkey11]

I know it is confusing, but tan^-1(x) is not the same as 1/tan(x)

From http://en.wikipedia.org/wiki/Trigonometric_functions#Inverse_functions :

arctan(x) = y <=> x = tan(y)

 

[T. D. W.]

arctan(x) = y <=> x = tan(y)

yes this is the thing that managed to let me understand, yet i now the problem is solved