ir/bench/mandelbrot.lua

-- By Erik Wrenholt

local BAILOUT = 16
local MAX_ITERATIONS = 1000

function iterate(x,y)

	local cr = y-0.5
	local ci = x
	local zi = 0.0
	local zr = 0.0
	local i = 0
	
	while 1 do
		i = i+1
		local temp = zr * zi
		local zr2 = zr*zr
		local zi2 = zi*zi
		zr = zr2-zi2+cr
		zi = temp+temp+ci
		if (zi2+zr2 > BAILOUT) then
			return i
		end
		
		if (i > MAX_ITERATIONS) then
			return 0
		end
	end

end

function mandelbrot()
	local t = os.clock()
	for y = -39, 38 do
		for x = -39, 38 do
			if (iterate(x/40.0, y/40) == 0) then
				io.write("*")
			else
				io.write(" ")
			end
		end
		io.write("\n")
	end
	io.write(string.format("Time Elapsed %.3f\n", os.clock() - t))
end

mandelbrot()
mandelbrot()