本例程为《控制系统数字仿真与CAD》第二章课后习题对应的matlab源程序，已调试完毕，保证正确。-This routine is " control system digital simulation and CAD" Chapter Homework corresponding matlab source code, has been debugged, to ensure correct.

本例程为《控制系统数字仿真与CAD》第三章课后习题对应的matlab源程序，已经过调试，确保正确。-This routine is " control system digital simulation and CAD" Chapter Homework corresponding matlab source code, has been debugged, to ensure correct.