  - Sine: Supports amplitude, phase shift, vertical shift, and period.
  - Cosine: Same as sine, but with the cosine function.
  
- Because I haven't worked out how to use Swift's `for x in x1...x2` with CGFloats, I use a where loop, 
- manually incrementing by our interval on each iteration. When the computation for an equation is finished, 
+ Because I haven't worked out how to use Swift's `for x in x1...x2` with CGFloats, I use a where loop,
+ manually incrementing by our interval on each iteration. When the computation for an equation is finished,
  I assign the collected values to the equation's `coordinates` property. The GraphView knows what to do with that.
  
  Also, the GraphView asks the Equations to compute as necessary, so you don't usually need to call this yourself.
  
  */
 
-//: Parabola
+//: Exponential
 
 class Exponential : GraphableEquation
 {
     var exponent : CGFloat = 0.0
-   
+    
     // MARK: - Initializers
     
     init(exponent: CGFloat)

    func reflect(overXAxis: Bool, overYAxis: Bool)
    
    func translate(deltaX: CGFloat, deltaY: CGFloat)

    func rotate(withAngle theta: CGFloat)
}


 
 */

func demo()
{
    let graph = GraphView(withSmallerXBound: -15.0, largerXBound: 15.0, andInterval: 0.5)
    let sine = Sine()
    let line = Line(slope: 1.0, offset: 4.0)
    let exponential = Exponential(exponent: 2.0)
    
    //: You can add these yourself.
    
//    let shiftedSine = Sine(period: 1.0, amplitude: 3.0, phaseShift: 1.0, verticalShift: 0.0)
//    shiftedSine.drawingColor = UIColor(red: 0.2, green: 0.2, blue: 0.7, alpha: 1.0)
//    
//    let cosine = Cosine()
//    cosine.drawingColor = UIColor(red: 0.2, green: 0.7, blue: 0.2, alpha: 1.0)
    
    graph.addEquation(sine)
    graph.addEquation(line)
    graph.addEquation(exponential)
    

    
    XCPlaygroundPage.currentPage.liveView = graph
}

demo()

