Is Adobe Acrobat's icon a special function?
The logo dates back to Adobe Reader v1.0. (link) I always thought it was chosen simply because it looks like the letter A for Acrobat.
A parametric function that approximates the logo is: $$x(t)=5\cos(t)\times \left(\sin(t+.5)+\cos(3t+.5) \right) \\ y(t)=5\sin(t)\times \left(\sin(t+.5)-\cos(3t+.5) \right) $$
It bears a strong resemblance to (in cartesian coordinates) $ x = \cos(t) + 3 \cos(2 t)/4, y = \sin(t) - 3 \sin(2 t)/4$ but not quite as symmetric.
Thanks you guys! Very grateful for this discussion. This is just what I was looking for. It's a Cinema4D Formula Object. Did a little Z tweaking to make it loop like Acrobat Logo. Apologies for my home made Z formula, kinda hacked at it. Sure there is a better solution.
- $X= 300 \cdot \cos(t) \cdot (\sin(t+.5) +\cos(3t+.5))$
- $Y= 300 \cdot \sin(t) \cdot (\sin(t+.5) -\cos(3t+.5))$
- $Z= 10 \cdot \cos(t) \cdot 10 \cdot \sin(t)$
- TMin $=-1.571$
- TMin $=1.571$