Before we start load seelogo by clicking on:

http://www.ithaca.edu/dani/talks/Talk_Nov_11/template.sl

The mathematical art language Seelogo will start and you will see the following program displayed in the edit window:  The name of the program is TCSR which stands for Translate Color Size Rotate

TCSR program:

t=0
LOOP 8000  [
 JT 0 0
 TRANS t  0  [COLOR colort  [SIZE (1+t^0.5)  [ROT t  [BOX 40 40]]]]
 JT 0 0
 TRANS -t 0  [COLOR colort  [SIZE (1+t^0.5)  [ROT -t  [BOX 40 40]]]]
 t=t+0.05]

On the left side of the screen you see a small box that has the name TCSR highlighted and another name:  colort
Click on colort   and you will see the program displayed in the edit window:

Local r g b c
r=127*(1+SIN (5*t^1.002))
g=90*(1+COS (2.1*t^1.002))
b=17*(1+SIN (4.33*t^1.002))
return RGB r g b

These two programs put together have the power to create beautiful mathematical designs.  During the hour you will create designs based on mathematical ideas and intuition.  At the last 10 minutes of the session we will share your creations.  Save your work in K;/faculty/Dani/Fun/Talk_Nov_11

What do you need to know?

1.  Colors:  Colors on PC's use the Red, Green. Blue combinations and the value of each component is between 0 and 255.  This explains the program colort above:  Since -1<=Sin(x)<=1 we have 0<=r<=254 where r=127*(1+SIN (5*t^1.002)) There is less Green and much less Blue.

The simplicity of the program allows for flexibility.  The inner shape BOX 40 40 is called the seed and one can change it using the language:
Example NGON 7 makes a polygon with 7 sides.
MT 0 50 JT 0 0 makes a vertical line
SPIN 12 [MT 0 50 JT 0 0]  makes 12 spokes
STARSKIP 3 7 makes a shape with 2 points where each third point is connected.  There are other options but most of the fun is in changing the functions that are applied to the 4 mathematical transformations.

ROT t [picture] means "rotate the picture by the amount specified".  It changes the orientation of the picture.  For example, you can type also ROT t*Sin(t/10) [picture] to get a gradual oscillating effect.
SIZE [t] [picture] changes the relative Size of the picture, so that SIZE 1 [picture]= picture and SIZE 2[picture] double[picture]
COLOR colort [picture] changes the picture w.r to the colort function that can be changed also
TRANS x y  [picture] moves (translates) the pictures tot he specified coordinates.

Once you get the hang of it the fun will be limitless and we cannot wait to see what pictures you create.