[JASS] Angle Tangent

[Saishy]

I have a Tangent, but I need an angle... How can I get an angle which Tangent is x?

 

[Eccho]

Hm I dont really understand.
How about demonstrating it with a picture._.?

 

[Saishy]

I have a Tangent... I need to know which angle have that tangent...

 

[Eccho]

I dont know if its because the time is very late, or im just dumb at the moment

The thing you want to do is:

you want to know the angle a if you have the distance r?

 

[Saishy]

well... yes... but tangent is the vertical line at the right-end of that circle.

 

[Eccho]

well, the vertical x-line is 0 degrees (I think you know that?)

Hm I guess im too tired :Z
What do you want to do?

Yu are aware of the "distance between points" and "angle between points" fuctions right?

 

[Saishy]

What I wanna to do? Get that angle...

I need this angle. Just that xD

 

[Eccho]

you mean you want angle a by only having x, or should you have r, as well...?

(>.> zzzZzzzz)

 

[donut3.5]

A tangent will be perpendicular to the angle from the circle. Since it touches the circle at only one point, you first must calculate the angle between the center of the circle and the point where the tangent touches. Since a perpendicular line is the negative reciprocal of the slope of the line it is perpendicular to, the angle should be 90+angle (look below for explanation).
Say you have a tangent that is touching the circle at the right side of the horizontal axis. Well, the angle between where the tangent touches the circle and the middle of the circle is 0, so the line has a slope of 1/0, and Arctangent of 1/0 is 90. As you increase the angle, the slope of the line from the center to the tangent will increase, and thus the reciprocal will decrease, and the Arctangent will increase.
First we need the angle between the two points:

Atan2(TangentPointY - CircleCenterY, TangentPointX - CircleCenterX)

Now that we have this angle, in order to get it into degrees, multiply it by bj_RADTODEG. To get your perpendicular, add 90.
Hope this helped,
--donut3.5--

 

[Eccho]

oO... I get what you mean...
My tiredness or my dumb lazy brain made me utter nothing

i go back from where I came from... The bed...

Much better having you here explaining, than having me understand 3% of the subjec^t._.

 

[Saishy]

But I'm not using circles...
Oh god, its not that kind of tangent...

Forget, I found this:

If you know the tangent ratio of an angle, finding the unknown angle is called the 'inverse tan' operation, and is often written as: tan-1 or atan.

So: tan 30.96375653° = 0.6
So: tan-1(0.6) = 30.96375653°

 

[Burning_Dragoon5]

This sounds like you're studying for some exams ^^

 

[donut3.5]

Then there's a thread on this already, I suggest you use search..

native Atan2 takes real y, real x returns real

--donut3.5--

 

[spiwn]

native Atan takes real x returns real

... is there a need to comment ...
P.s. A stands for Archus or something(not sure of exact English translation)

 

[Saishy]

Then there's a thread on this already, I suggest you use search..

native Atan2 takes real y, real x returns real

--donut3.5--

Yeah but I don't know how to search for this. I tried somethings and didn't find.

And how I use that Atan2? Or Atan?

 

[spiwn]

If you have the tangent you should use Atan.
To use it in GUI it is in Math - ArcTan(from angle)
Or Custom Script local real angle=Atan (tangent)
Or Custom Script set angle=Atan(tangent)

 

[Saishy]

thanks ^^