画箭头用的一个matlab程序，箭头是二维度的，需要说如箭头大小的控制参量-draw an arrow,only the two dimmentional arow,and the arrow is composed of three lines,two short an one long,the results may not viry beatuiful but is very simple

matlab中没有画箭头函数。这个程序在matlab图像中画箭头-plot arrows in matlab figure.