Wondering about learning Python

[Grant Edwards]

On 2004-07-22, Chris <nospam@[> wrote:

> I've written a small QBASIC program which draws a spiral. Here is the 
> code:
>
> SCREEN 12
> CLS
> FOR t = 1 TO 400 STEP .01
> x = .5 * t * COS(t)
> y = .5 * t * SIN(t)
> PSET (x + 320, y + 240)
> NEXT t
>
> I noticed that it generated some interesting patterns, probably as a 
> result of rounding errors.

I suspect the patterns to which you refer are the moire
patterns generated when you superimpose the pattern you are
drawing and the two "grids" imposed by the rasterizaion done by
your frame buffer and the grid formed by the phosphor dots and
shadow mask of your CRT.

http://www.mathematik.com/Moire/
http://www.exploratorium.edu/snacks/moire_patterns.html
http://eluzions.com/Illusions/Moire/

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