压缩文件中包含五个matlab程序，可用于求解信号与系统常用信号（如双边、单边指数信号、门函数等）的傅立叶变换并图形显示变换结果-compressed file contains five Matlab procedures, can be used for signal and the signal system used (such as bilateral, unilateral index signal gate function) of the Fourier transform an