% julia sets, but programmed with MATLAB tricks

c = input('Enter complex parameter -> ');

if abs(c)>=2
	disp('Warning: Using a parameter with absolute value')
	disp('greater than 2 is not recommended.');
end;

z0 = input('Please enter lower left corner -> ');
z1 = input('Please enter upper right corner -> ');

x0 = real(z0);
y0 = imag(z0);

x1 = real(z1);
y1 = imag(z1);

maxsteps = input('Please enter escape time -> ');

hres = input('Please enter horizontal resolution -> ');

vres = ceil( abs( hres * (y1-y0)/(x1-x0)) );

dx = (x1-x0)/hres;
dy = (y1-y0)/vres;


[X,Y] = meshdom(x0:dx:x1, y0:dy:y1);

z = X + Y*i;
c = c*ones(size(z));
pict = 0*z;
clear X Y

for k=1:maxsteps
	bigs = find(abs(z)>=2);
	pict(bigs) = k*ones(size(bigs));
	z(bigs) = zeros(size(bigs));
	c(bigs) = zeros(size(bigs));
	z = z.^2 + c;
end;




image(flipud(pict))
axis('image')
axis('xy')
axis('off')

% uncomment exactly one of the following lines:
%colormap(gray(maxsteps))	% for gray-scale monitors
colormap(hsv(maxsteps))		% for color monitors