la_fo_tr.m

经典《信号与系统》教程的matlab例程,对深入理解信号与系统相关概念有很大帮助

%==================================================================
% Name: flt.m
% This program can be used to obvious the relationship
% between the zero-pole location and the time and frequency domain
% characteristics of the rectangular pulse.
%==================================================================
clear,close all;
p=0.01;
t=-5:p:5;
x=u(t+0.1)-u(t-0.1);
a=-0:0.4:5;
b=-20:0.4:20;					
[a,b]=meshgrid(a,b);
c=a+i*b;						%确定绘图区域
X=x*exp(-t'*c)*p;
%c=(1-exp(-2*(c+eps)))./(c+eps);
%c=abs(c);						%计算拉普拉斯变换

subplot(2,1,1)
mesh(a,b,c);					%绘制曲面图
surf(a,b,c);
view(-60,20)					%调整观察视角
axis([-0,5,-20,20,0,2]);
title('The Laplace transform of the rectangular pulse');
%colormap(hsv);
w=-20:0.1:20;
Fw=(2*sin(w+eps).*exp(i*(w+eps)))./(w+eps);
subplot(2,1,2);plot(w,abs(Fw))
title('The Fourier transform of the rectangular pulse')
xlabel('frequence w')
%=========================================================