
7th October 2001, 23:30  #1 
Forum King

Sin, Cos, Tan
I learned in my geometry class that sine, cosine, and tangent were triangle angle ratios. Exactly how do sin, cos, and tan effect superscopes and movements. I heard something about triangle angle ratios being in degress and superscopes and movements being in rads, but I don't know what that means. Can somebody please explain this to me?
 
8th October 2001, 15:30  #2 
Banned

well,
i find that this will do fine for movement:
code: 
9th October 2001, 22:38  #3 
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Trigonometry :)
The easiest way to explain is this:
Given a circle with radius 1 (the so called 'unitcircle'). We take a random point on this circle. We can describe this point uniquely by the angle of the radius through this point and the Xaxis, for example 90°, 140°, ... Mathematically however, radians are used instead of degrees. Without going into much theory, you should just remember that 360° = 2*PI. So suppose we have a point lying at N radians on our unit circle. Then the X coordinate will be given by cos(N), and the Y coordinate by sin(N). That's the definition of cosine and sine. So if you want to draw a circle, take every value A from 0 to 2*PI, and plot the points (cos(A), sin(A)). Easy. The relationship of sine and cosing with rightangled triangles is pretty easy to see. Draw a circle using the origin (0,0) as center. Take a point on this circle, connect the point with the center, project the point on the X axis. Voilà: a rightangled triangle appears Sin and cos have other uses as well. Because they are coordinates of points lying on a circle, they are periodic. A point traveling along a circle will eventually arrive at its starting point. This means that their values are repetive after a while (2*PI to be exact). So you can use sine and cosine as a source for a pulsing/wavy scope or movement. The tangent tan is defined as sin divided by cos. It ranges from negative infinity to positive infinity in PI/2 to PI/2, and repeates itself every PI. Usually you won't need the actual mathematical uses of these functions, but you'll rather be using their characteristics (e.g. repetiveness). 
10th October 2001, 00:57  #4 
Forum King

Thanks uncloned. That makes more sence to me.
 
12th October 2001, 19:21  #5 
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Nick :)
While I'm pretty sure I have not been cloned, I'd appreciate it if you'd stick to my actual nickname

13th October 2001, 02:56  #6 
Forum King

sorry, finger sliped
 
28th October 2001, 04:34  #7 
Junior Member

I Want to Learn About Sin, Cos
I Want to Make Cool Equations on My AVS Editor but i Don´t Know very few About Sin, Cos, Tan ... Where can I Get Documentation about it??
If You Have Documentation about it, please send me! 
16th November 2001, 21:11  #8 
Senior Member
Join Date: Oct 2001
Posts: 145

There's also arcsine(asin), arccosine(acos) and arctangent(atan).
I find that d=atan(d) has a nice effect as demonstrated in Justin's ageold plugin that's no longer available, Gold Shower in Pseudo 3D. 
17th November 2001, 01:04  #9 
Forum King

Justin didn't make it. Lone did. It was in an older version of winamp. Justin removed a blur and added biliner filtering because bilinear filtering wasn't there when lone made it.
 
17th November 2001, 13:06  #10 
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Sorry...Lone made it but it was sweet.

22nd December 2002, 21:56  #11 
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This is off the subject, but
I noticed something. If you highlight (click and drag) over a smiley face emoticon, it turns to a sad face! Well, sort of.

23rd December 2002, 00:59  #12 
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Only in browsers that don't support true alphablending (*cough*IE*cough*)

23rd December 2002, 01:52  #13 
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What does that mean?

23rd December 2002, 01:53  #14 
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Oh wait, I got it.

23rd December 2002, 21:37  #15 
Forum King

1: Use the edit button
2: Don't revive dead posts for no reason "guilt is the cause of more disauders than history's most obscene marorders" E. E. Cummings 
24th December 2002, 21:09  #16 
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ack!
What! This post is a zombie! AAhhhh! (sorry, couldn't help it)


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