Comments on: Example 13-6: Oscillation

By: Daniel Shiffman

Daniel Shiffman — Thu, 20 Jan 2011 14:52:44 +0000

@Dave, whoops yes, that is an error will fix now!

Daniel Shiffman — Mon, 17 Jan 2011 21:41:15 +0000

You must have a parentheses out of place or something, this works no problem:

  float r = width/2;
  float x = (sin(theta) + 1) * r;

Also, if you declared r above setup() then widht won’t have been set yet and the value would be 0.

MD — Mon, 17 Jan 2011 04:11:13 +0000

I noticed a small quirk with this statement,
float x = (sin(theta) + 1) * width/2;

When \width/2\ is replaced by a variable \float r = width/2\, the ellipse doesn’t oscillate. Does anyone know why?

Dave — Mon, 22 Nov 2010 15:17:28 +0000

the code says

// The output of the sin() function oscillates smoothly between 1 and 1.

should this not say:

// The output of the sin() function oscillates smoothly between -1 and 1.

confused me a bit.