dm13103.m

the code of the book come form the book of marlix laboratory with the book of singal

%dm13103
%计算离散序列Z变换
syms  n w;               %定义离散时间符号变量n
X=cos((pi*n)/4);         %定义离散时间符号表达式X
Z=ztrans(X,w)            %计算自变量为w的z变换的符号表达式