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Sin, Cos, Tan

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  • 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?

  • #2

    i find that this will do fine for movement:


    • #3

      The easiest way to explain is this:

      Given a circle with radius 1 (the so called 'unit-circle'). 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 X-axis, 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 right-angled 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 right-angled 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).


      • #4
        Thanks uncloned. That makes more sence to me.


        • #5

          While I'm pretty sure I have not been cloned, I'd appreciate it if you'd stick to my actual nickname


          • #6
            sorry, finger sliped


            • #7
              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!


              • #8
                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 age-old plugin that's no longer available, Gold Shower in Pseudo 3D.


                • #9
                  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.


                  • #10
                    Sorry...Lone made it but it was sweet.


                    • #11
                      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.


                      • #12
                        Only in browsers that don't support true alphablending (*cough*IE*cough*)


                        • #13
                          What does that mean?


                          • #14
                            Oh wait, I got it.


                            • #15
                              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