[RESOLVED] Angle from 0,0 to x,y

[Creative Action]

As a beginner I'm thrashing out an application and I want to figure most of it out on my own. But being a math dork I can't figure out the equation (or function) that yields the angle of the line from 0,0 to the mouse x,y.

I want to click and drag the minute hand around a clock face.

Thanks.

[Eager Beaver]

Please see the attached FLA (F8).
Hope this is what you asked.

[Creative Action]

Nice, just what I was looking for.

This is the part that is a little mysterious to me. Why choose "th" as a variable name? I guess I should pull a trig text and brush up on this. The whole radian to angle thing confuses me.

th=Math.atan2(yl,xl);
an=th*180/Math.PI;

Now to struggle with the rest.

[Eager Beaver]

For calculating the trigonometric functions FLASH requires that the angle should be in radians (th).
0 radians=0 degrees.
PI (3.141592654) radians=180 degrees.
For using the _rotation function FLASH requires that the angle should be in degrees (an).
an=th*180/Math.PI;
I hope I could it make clear, otherwise please read a good book on trigonometry, and flash programming.

[newblack]

Eager Beaver-

Creative Action was confused by your variables' names. i assume by 'th' you're truncating 'theta' and by 'an' you're truncating 'angle.' It never hurts to be overly descriptive in your variable name- especially when the goal is to help someone out...

[Eager Beaver]

Thank you for your suggestion.
Yes, you are correct:
th==theta (radians).
an==angle (degrees).
There are many abbreviations in the net nowadays.
LOL: Laugh Out Loud.
OMG: Oh My God.
ASAP: As Soon As Possible.
And so on.

[newblack]

Thank you for your suggestion.
Yes, you are correct:
th==theta (radians).
an==angle (degrees).
There are many abbreviations in the net nowadays.
LOL: Laugh Out Loud.
OMG: Oh My God.
ASAP: As Soon As Possible.
And so on.

abbreviation has its place...

[Eager Beaver]

I think you prefer to pick up an argument on this subject.
I thought there were no rules not to assign names such as, th, an, to variables.
I have already agreed with your suggestion.

[newblack]

I think you prefer to pick up an argument on this subject.

no- just lulz

I thought there were no rules not to assign names such as, th, an, to variables.

of course not- but if you want your code to be comprehensible, it's a different story. i mean why th? why stop there? why not t?

I have already agreed with your suggestion.

the above would indicate otherwise, but time will tell!

[Eager Beaver]

no- just lulz
of course not- but if you want your code to be comprehensible, it's a different story. i mean why th? why stop there? why not t?
the above would indicate otherwise, but time will tell!

Yes you can use t or th or the or thet or theta, and the FLA works without any problem.
I have already agreed with your suggestion to use variable names theta and angle so that Creative Action understands the CODE with ease.

[Creative Action]

Thank you Eager Beaver and newblack, th being Theta is exactly what I was looking for. The other abreviations were apparent to me. And I plead guilty to needing to read a Trig Text. Can you suggest a really good AS2 book? I'm considering Lynda.coms AS3 DVD, what do you think? Basically, I am always guilty of coming up with some overly complex project and then beating my head against it until I learn the program. My very first 3D modeling project was a pirate ship with everything.

[Eager Beaver]

I suggest for flash8, and AS2, flash bible.
I don't know AS3.