在MATLAB并无直接指令可进行画圆，本程序是一个不错的画圆程序。-in MATLAB no direct instructions can be Circle, the procedure is a good Circle procedures.

Draw a circle in a matrix using the integer midpoint circle algorithm. Code does not miss or repeat pixels.

史密斯图(Smith chart)是一款用于电机与电子工程学的图表，主要用于传输线的阻抗匹配上。在复平面上采用双线性变换。实部 r=常数和虚部 x=常数，两族正交直线变化为正交圆并与反射系数|G|=常数和虚部x=常数套用而成。本文档通过MATLAB来编写程序，绘制一个完整的SMITH圆图-Smith figure (Smith chart) is a for electrical and electronic engineering chart, mainly for the transmiss