基于MATLAB的连续性信号的采样与重构

基于MATLAB的连续性信号的采样与重构
对于一个连续性周期函数如cos(a*pi*t)+sin(b*pi*t),如何利用matlab实现它的采样与重构,希望大家给出重构公式以及matlab中具体的程序做法.

程度如下：
% --- Executes on button press in pushbutton1.
function pushbutton1_Callback(hObject,eventdata,handles)
% hObject handle to pushbutton1 (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
a=str2double(get(handles.a,'String'));
b=str2double(get(handles.b,'String'));
t=0:0.01:10;
x=cos(a*pi*t)+sin(b*pi*t);
axes(handles.axes1);
plot(t,x);
xlabel('t'),ylabel('f1');
grid on;
y=fft(x);
f=(0:length(y)-1)'/length(y);
axes(handles.axes2);
plot(f,y);
xlabel('ω'),ylabel('F(ω)');
grid on;
end
% --- Executes on button press in pushbutton2.
function pushbutton2_Callback(hObject,eventdata,handles)
% hObject handle to pushbutton2 (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
%set(handles.a,'String','');
%set(handles.b,'String','');
axes(handles.axes1);
cla reset;
axes(handles.axes2);
cla reset;
% --- Executes on button press in pushbutton3.
function pushbutton3_Callback(hObject,eventdata,handles)
% hObject handle to pushbutton3 (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
cai2;
delete(handles.figure1);
% --------------------------------------------------------------------
function cai1_Callback(hObject,eventdata,handles)
% hObject handle to cai1 (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
% --------------------------------------------------------------------
function cai2_Callback(hObject,eventdata,handles)
% hObject handle to cai2 (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)