lorentz.bash

#!/bin/bash -xv

cat << FIN > /tmp/header
P2
600 600
255
FIN

###真っ黒な画###
seq -w 0 359999 > /tmp/body

yes                                             |
awk -v "x=1" -v "y=2" -v "z=3"\
    -v "p=10" -v "r=28" -v "b=2.666666" -v "dt=0.001" \
    '{dx=(-p*x+p*y)*dt;dy=(-x*z+r*x-y)*dt;dz=(x*y-b*z)*dt;\
     print x,y,z;x+=dx;y+=dy;z+=dz}'            |
###画像の座標に変換###
awk '{print int($2*10)+300, int($1*10)+300}'    |
###PGMのピクセルの順番に変換###
awk '{print $1+$2*600, 255}'                    |
head -n 50000                                   |
sort -u -k1,1n                                  |
maezero 1.6                                     |
loopj num=1 /tmp/body -                         |
awk '{print $2}'                                |
cat /tmp/header - > /tmp/lorentz.pgm

convert /tmp/lorentz.pgm ./lorentz.png