David Little
Mathematics Department
Penn State University
Eberly College of Science
University Park, PA 16802
Office: 403 McAllister
Phone: (814) 865-3329
Fax: (814) 865-3735
e-mail:dlittle@psu.edu

Sample SpiroGraphs
 Name Radius1 Radius2 Position Resolution Comments Cardioid 60 60 60 270 See what happens when you vary the postion to the left or to the right. How could you get a cardioid oriented differently? Astroid 60 -15 -15 270 Another name for an astroid is a hypocycloid of four cusps. What would you change to get the same picture rotated 45 degrees? Vary the radius and try to get 3,5 or 6 cusps. Also, vary the position and see what happens. Four-leaved rose 60 -15 45 270 Try to vary the radius and postion to get 3,5 or 6 leaves Vertical Line 60 -30 -30 270 What would you change to get a horizontal line? Ellipse 60 -30 -90 270 What would you have to change in order to get an ellipse oriented horizontally? How would you get an ellipse on the inside of the fixed circle? Rounded Square 60 -45 -101 270 How about a rounded triangle or pentagon? Gold fish 75 -25 85 270 This is supposed to be fun, right? Star fish 75 -30 60 270 Come on, you're enjoying this! Spiral In, Spiral Out 5 60 60 270 Rotating Triangle 90 1 105 270 Change the value of Radius 1 just slightly, and see how much the Spirograph changes!! Make sure to turn the velocity down low, or the drawing will take place too fast to see the triangle being rotated. Experiment with Resolution 60 1 122 60 Try changing the Resolution to 61, 62, 63. How do you explain this behavior? String of Pearls 100 49 66 7 Orbit 60 59 80 1 Make sure you turn the velocity down low. See what happens when you change the value of Radius2 to 61. Change the resolution to 2 and you'll be seeing double. Bubbles 80 -20 -20 270 20 20