Spirograph

Spirograph
The Spirograph applet is written using Java. You must have a Java enabled browser such as Netscape Navigator or Microsoft IE to be able to see this Spirograph applet.
You can display this spirograph on your own homepage. See below.

What is a Spirograph?
A Spirograph is a curve formed by rolling a circle inside or outside of another circle. The pen is placed at any point on the rolling circle. If the radius of fixed circle is R, the radius of moving circle is r, and the offset of the pen point in the moving circle is O, then the equation of the resulting curve is defined by:
x = (R+r)*cos(t) - (r+O)*cos(((R+r)/r)*t)
y = (R+r)*sin(t) - (r+O)*sin(((R+r)/r)*t)
How to use it?
Here is how you can use the controls in this Spirograph applet:

The first three scroll bars in the control panel let you change R, r and O respectively.

You can use the next three scroll bars to change the color of the drawing. These scroll bars change the red, green and blue values of the color (in the range 0-255) respectively.

The last scroll bar lets you choose the number of iterations for the Spirograph. Move it to beginning and then slowly increase it to see how many iterations it takes to complete the spirograph.

You can use the Random button to select random values for the radii and color. The number of iterations is not changed by the Random button.

How to put this applet on your homepage?
Embed following HTML code in your page. That's all! Feel free to change the initial values of the radii in the code below. Feel free to drop me a note with the address of the page where you display it.
<APPLET CODEBASE="http://wordsmith.org/anu/java/" CODE="Spiro.class" width=680 height=400>
<PARAM NAME="R" VALUE="20">
<PARAM NAME="smallr" VALUE="5">
<PARAM NAME="O" VALUE="70">
<PARAM NAME="redBits" VALUE="242">
<PARAM NAME="greenBits" VALUE="255">
<PARAM NAME="blueBits" VALUE="139">
<PARAM NAME="I" VALUE="400">
</APPLET>
<BR>
Created by <A HREF="http://wordsmith.org/anu/">Anu </A>
<A HREF="http://wordsmith.org/anu/">Garg</A>.
<P>
I have suggestions for improving this applet?
Your comments are welcome at gargATwordsmith.org.
Download
Compressed zip file with source, bytecode and all supporting files: spirograph.zip

Where can I buy the good old spirograph I can touch and hold?
If you'd rather have a spirograph made of atoms rather than bits, you can buy one at Amazon.com.
Awards

Anu Garg