--------------- 函數f(t)=t的圖形
origin is (200, 300);						-- 設置原點的偏移量
rot is pi/6;								-- 設置旋轉角度
scale is (2, 1);							-- 設置橫坐標和縱坐標的比例
for T from 0 to 200 step 1 draw (t, 0);		-- 橫坐標的軌跡
for T from 0 to 180 step 1 draw (0, -t);	-- 縱坐標的軌跡
for T from 0 to 150 step 1 draw (t, -t);	-- 函數f(t)=t的軌跡