盒计数法，差分盒计数法，毯子法，来实现分形维数的计算
资源文件列表
fenxing/box1.m , 1170
fenxing/box2.m , 854
fenxing/box_frac_dem.m , 962
fenxing/brown.m , 2979
fenxing/chafenbox.m , 76
fenxing/den.m , 30
fenxing/density.m , 1586
fenxing/fenshubrown.m , 149
fenxing/multifractal.m , 2809