Phil_Bowers.henr801E@XEROX.COM (08/18/89)
To all interested in the Kock 'snowflake curve' program;
Sorry, but I am using a STAR and couldn't find the caret "^"character for
exponents so I used "**" which appears to have caused some confusion. Line
#90 SHOULD READ:
090 L=SQR((X(P)-X(P-1))^2+(Y(P)-Y(P-1))^2)
In the way of a peace offering, I offer you the following program which
was written from the equations given in the book "CHAOS".
0 REM from "CHAOS" by James Gleick
1 REM "Attractor of Henon"
10 HGR2: HCOLOR=3
15 MX=100:MY=200: REM Magnifly on X and/or Y axis
20 XC=140:YC=96:REM centers image on screen
40 X=0.1:Y=0.1
50 XN=Y+1-(1.4*X^2)
60 YN=0.3*X
70 HPLOT XN*MX+XC,YN*-MY+YC
80 X=XN:Y=YN
90 GOTO 50
This ends up looking like a boomerang with one end broken off. If you
increase the values MX or MY, to make any section larger, you will have to
include a test to only HPLOT points that remain on the screen since this
program generates positive and negative for X and Y.
phil