function jibanyan_equation(x, y)
min(max(min(1-(x/108)^2-(y/94)^2,y),
min(1-((abs(x)-119)/103)^2-((y-56)/86)^2,
1-((abs(x)-15)/77)^2-((y-119)/100)^2),
1-((abs(x)-42)/66)^2-(y/55)^2,
min(55+y,51-abs(x),-y)),
3*abs(y-100)-2*(x-75)) * min(min(max(min(1-(x/106)^2-(y/92)^2,y),
min(1-((abs(x)-119)/101)^2-((y-56)/84)^2,
((abs(x)-99)/40)^2+((y-54)/86)^2-1,92-abs(x)),
1-((abs(x)-42)/64)^2-(y/53)^2),
min(((abs(x)-52)/26)^2+((y+28)/26)^2-1,
((abs(x)-51)/13)^2+(y/13)^2-1,
max(abs(x)-51,y))),abs(x/51+10/51*sin(abs(y/61.2)^(1.2)*pi*(7/2)))^(2/3)+abs(y/61.2)^(2/3)-1) * min(1-(x/32)^2-((y+30)/32)^2,
1-((abs(x)+5)/22)^2-((y-18)/22)^2) * min(1-((abs(x)-18)/20)^2-((y+10)/20)^2,
((abs(x)-20)/22)^2+((y+7)/20)^2-1) * (1-((abs(x)-51)/11)^2-(y/11)^2)
end
using Gadfly
plot(z=(x,y) -> jibanyan_equation(x, y),
x=linspace(-150,150,1000), y=linspace(-150,150,1000), Geom.contour(levels=[0]))
Geom.contourのオプションにlevels=[0]を指定しないと残念な結果になる。
