【正文】 (varargin)gui_Singleton = 1。gui_State = struct(39。gui_Name39。, mfilename,...39。gui_Singleton39。, gui_Singleton,...39。gui_OpeningF39。, @df_OpeningF,...39。gui_OutputF39。, @df_OutputF,...39。gui_LayoutF39。, [] ,...39。gui_Callback39。, [])。if nargin amp。amp。 ischar(varargin{1}) = str2func(varargin{1})。endif nargout[varargout{1:nargout}] = gui_mainf(gui_State, varargin{:})。elsegui_mainf(gui_State, varargin{:})。endfunction df_OpeningF(hObject, eventdata, handles, varargin) = hObject。guidata(hObject, handles)。function varargout = df_OutputF(hObject, eventdata, handles)varargout{1} = 。function edit1_Callback(hObject, eventdata, handles)function edit1_CreateF(hObject, eventdata, handles)if ispcset(hObject,39。BackgroundColor39。,39。white39。)。elseset(hObject,39。BackgroundColor39。,get(0,39。defaultUicontrolBackgroundColor39。))。endfunction edit2_Callback(hObject, eventdata, handles)function edit2_CreateF(hObject, eventdata, handles)if ispcset(hObject,39。BackgroundColor39。,39。white39。)。elseset(hObject,39。BackgroundColor39。,get(0,39。defaultUicontrolBackgroundColor39。))。endfunction edit3_Callback(hObject, eventdata, handles)function edit3_CreateF(hObject, eventdata, handles)if ispcset(hObject,39。BackgroundColor39。,39。white39。)。elseset(hObject,39。BackgroundColor39。,get(0,39。defaultUicontrolBackgroundColor39。))。endfunction edit4_Callback(hObject, eventdata, handles)function edit4_CreateF(hObject, eventdata, handles)if ispcset(hObject,39。BackgroundColor39。,39。white39。)。elseset(hObject,39。BackgroundColor39。,get(0,39。defaultUicontrolBackgroundColor39。))。endfunction edit5_Callback(hObject, eventdata, handles)function edit5_CreateF(hObject, eventdata, handles)if ispcset(hObject,39。BackgroundColor39。,39。white39。)。elseset(hObject,39。BackgroundColor39。,get(0,39。defaultUicontrolBackgroundColor39。))。endfunction pushbutton1_Callback(hObject, eventdata, handles)f=zeros(1,4)。f(1)=str2num(get(,39。String39。))。f(2)=str2num(get(,39。String39。))。f(3)=str2num(get(,39。String39。))。f(4)=str2num(get(,39。String39。))。T=str2num(get(,39。String39。))。%采樣周期% fre=str2num(get(,39。String39。))。%采樣頻率% t=0:1/fre:T。xn=10*sin(2*pi*t*f(1))+10*sin(2*pi*t*f(2))+10*sin(2*pi*t*f(3))+10*sin(2*pi*t*f(4))。set(,39。userdata39。,xn)。%將Xn放在用戶數據userdata% yn3=abs(fft(xn))。%快速傅立葉變換（符頻特性）% n1=[0:length(yn3)1]/length(yn3)*fre。%橫坐標% axes()。%坐標系編號% stem(n1,yn3,39。.39。)。axis([0,fre/2,0,max(yn3)])。%坐標軸單位控制% title(39。信號的幅頻特性39。)。xlabel(39。頻率（Hz）39。)。ylabel(39。|X(ejw)|39。)。yn4=angle(fft(xn))。%相頻特性%n4=[0:length(yn4)1]/length(yn4)*fre。axes()。stem(n4,yn4,39。.39。)。axis([0,fre/2,min(yn4),max(yn4)])。title(39。信號的相頻特性39。)。xlabel(39。頻率（Hz）39。)。ylabel(39。相位39。)。function edit6_Callback(hObject, eventdata, handles)function edit6_CreateF(hObject, eventdata, handles)if ispcset(hObject,39。BackgroundColor39。,39。white39。)。elseset(hObject,39。BackgroundColor39。,get(0,39。defaultUicontrolBackgroundColor39。))。endfunction edit7_Callback(hObject, eventdata, handles)function edit7_CreateF(hObject, eventdata, handles)if ispcset(hObject,39。BackgroundColor39。,39。white39。)。elseset(hObject,39。BackgroundColor39。,get(0,39。defaultUicontrolBackgroundColor39。))。endfunction edit8_Callback(hObject, eventdata, handles)function edit8_CreateF(hObject, eventdata, handles)if ispcset(hObject,39。BackgroundColor39。,39。white39。)。elseset(hObject,39。BackgroundColor39。,get(0,39。defaultUicontrolBackgroundColor39。))。endfunction edit9_Callback(hObject, eventdata, handles)function edit9_CreateF(hObject, eventdata, handles)if ispcset(hObject,39。BackgroundColor39。,39。white39。)。elseset(hObject,39。BackgroundColor39。,get(0,39。defaultUicontrolBackgroundColor39。))。endfunction pushbutton2_Callback(hObject, eventdata, handles)xn=get(,39。userdata39。)。fre=str2num(get(,39。String39。))。fp=str2num(get(,39。String39。))。%通帶最大頻率 % fs=str2num(get(,39。String39。))。%阻帶最小頻率% rp=str2num(get(,39。String39。))。rs=str2num(get(,39。String39。))。wp=2*fp/fre。ws=2*fs/fre。[N,wc]=buttord(wp,ws,rp,rs,39。s39。)。%求階數，截止頻率%[B,A]=butter(N,wc,39。s39。)。%巴特沃茲模擬低通濾波器系數%[Bz,Az]=bilinear(B,A,1)。[H,w]=freqz(Bz,Az)。%分析數字濾波器% axes()。plot(w/pi,abs(H))。axis([0,1,0,max(abs(H))])。title(39。巴特沃茲的幅頻特性39。)。xlabel(39。w/π39。)。ylabel(39。|X(ejw)|39。)。axes()。plot(w/pi,angle(H))。title(39。巴特沃茲的相頻特性39。)。xlabel(39。頻率（Hz）39。)。ylabel(39。相位39。)。yn2=filter(Bz,Az,xn)。%迭代法求解濾波信號% yn=abs(fft(yn2))。n1=[0:length(yn)1]/length(yn)*fre。axes()。stem(n1,yn,39。.39。)。title(39。信號濾波后的幅頻特性39。)。xlabel(39。頻率（Hz）39。)。ylabel(39。|X(ejw)|39。)。axis([0,fre/2,0,max(yn)])。yn=angle(fft(yn2))。n1=[0:length(yn)1]/length(yn)*fre。axes()。stem(n1,yn,39。.39。)。title(39。信號濾波后的相頻特性39。)。xlabel(39。頻率（Hz）39。)。ylabel(39。相位39。)。axis([0,fre/2,min(yn),max(yn)])。pushbutton1_Callback(hObject, eventdata, handles)。function edit10_Callback(hObject, eventdata, handles)function edit10_CreateF(hObject, eventdata, handles)if ispcset(hObject,39。BackgroundColor39。,39。white39。)。elseset(hObject,39。BackgroundColor39。,get(0,39。defaultUicontrolBackgroundColor39。))。endfunction edit11_Callback(hObject, eventdata, handles)function edit11_CreateF(hObject, eventdata, handles)if ispcset(hObject,39。BackgroundColor39。,39。white39。)。elseset(hObject,39。BackgroundColor39。,get(0,39。defaultUicontrolBackgroundColor39。))。endfunction pushbutton5_Callback(hObject, eventdata, handles)xn=get(,39。userdata39。)。fp=str2num(get(,39。String39。))。fs=str2num(get(,39。String39。))。fre=str2num(get(,39。String39。))。wp=2*fp/fre*pi。ws=2*fs/fre*pi。Bt=wswp。N0=ceil(*pi/Bt)。N=N0+mod(N0+1,2)。wc=(wp+ws)/2/pi。hn=fir1(N1,wc,boxcar(N))。%單位序列相應%yn=abs(fft(hn))。yn=20*log10(yn)。n1=[0:length(yn)1]/length(yn)*2。axes()。plot(n1,yn)。title(39。矩形窗的損耗函數39。)。xlabel(39。w/π39。)。ylabel(39。20log|Hg(w)|39。)。axis([0,1,min(yn),max(yn)])。axes()。yn=angle(hn)。n1=[0:length(yn)1]/length(yn)*2。plot(n1,yn)。title(39。矩形窗的相頻特性39。)。xlabel(39。w/π39。)。ylabel(39。相位39。)。axis([0,1,min(yn),max(yn)])。yn2=fftfilt(hn,xn,512)。%重疊相加法求濾波后序列% yn=abs(fft(yn2))。n1=[0:length(yn)1]/length(yn)*fre。axes()。stem(n1,yn,39。.39。)。title(39。信號濾波后的幅頻特性39。)。xlabel(39。頻率（Hz）39。)。ylabel(39。|X(ejw)|39。)。axis([0,fre/2,0,max(yn)])。yn=angle(fft(yn2))。n1=[0:length(yn)1]/