实验三抽样

3.1正弦信号混叠

 A.

程序：

 >>nn=0:79;

 >>sinus=sin(2*pi*300/8000*nn);

 >>stem(nn,sinus)

.b.

程序：

 >>plot(nn,sinus)

 

.c.

  >> nn=0:79;

sinus=sin(2*pi*100/8000*nn);

>> x1=sinus;

>> nn=0:79;

sinus=sin(2*pi*225/8000*nn);

>> x2=sinus;

>> nn=0:79;

sinus=sin(2*pi*350/8000*nn);

>> x3=sinus;

>> nn=0:79;

sinus=sin(2*pi*475/8000*nn);

>> x4=sinus;

>> subplot(411),stem(nn,x1);

>>  subplot(412),stem(nn,x2);

>>  subplot(413),stem(nn,x3);

>>  subplot(414),stem(nn,x4);

3.3产生信号

a,

n=0:1000;

f0=1000;

fsim=80000;

t=n./fsim;

x=cos(2*pi*f0*n/fsim);

subplot(211),stem(n,x);

title('SAMPLES'),ylabel('x(t)'),xlabel('n');

subplot(212),plot(t,x);

title('CONTINIOUS'),ylabel('x(t)'),xlabel('t')

c.

fmagplot函数m文件：

function fmagplot(xa,dt)

L=length(xa);

Nfft=round(2.^round(log2(5*L)));

Xa=fft(xa,Nfft);

range=0:(Nfft/4);

ff=range/Nfft/dt;

plot(ff/1000,abs(Xa(1:length(range))))

title('CONT-TIME FOURIER TRANSFORM(MAG)')

xlabel('FREQUENCY(kHz)'),grid;

Pause

fmagplot(x,1/fsim)

3.4 A/D转换

a.

fsim=80000;

fs=8000;

k=fsim/fs;

n=0:1000;

l=length(n);

x=cos(2*pi*1000*n/fsim);

y=x(1:k:l);

L=length(y);

n1=0:L-1;

stem(n1,y)

title('AD'),ylabel('x[n]'),xlabel('n')

b.

[H,W]=dtft(y,1000);

plot(W,abs(H));

title('DTFT AD'),ylabel('X(jw)'),xlabel('w')

3.5设计一个重建滤波器

B.

fsim=80000;                                   

f0=1000;

fs=8000;

y2=zeros(1,L);

for i=0:L1-1;

    y2(i*delta+1)=y(i+1);

end

fcut=2*(fs/2)/fsim;                                  

[b,a]=cheby2(9,60,fcut);                             

x1=delta*filter(b,a,y2);                                

[c,d]=freqz(b,a,1000,'whole');

d(501:1000)=d(501:1000)-2*pi;

d=fftshift(d);

d=d/2/pi/1000*fsim;

c=fftshift(c);

plot(d,abs(c));ylabel('|H(j\omega)|');xlabel('FREQUENCY(kHz)');

3.6 D/A转换：

a.

y2=zeros(1,L);

for i=0:100;

    y2(i*10+1)=y(i+1);

end

yy=filter(b,a,y2);

t=[0:0.001:1];

plot(t,yy)

ylabel('xr(t)'),xlabel('t')

b.

fmagplot(yy,0.0000125)

3.7测试混叠

function [x,x1,y,y1,y2]=testall(f0,fs,fsim)

n=0:1000;                                     

fsim=80000;                                    

dt=1/fsim;                                     

t=n./fsim;                                     

x=cos(2*pi*f0*n/fsim);                        

delta=round(fsim/fs);                              

L=length(x);

y1=zeros(1,L);

y1(1:delta:L)=x(1:delta:L);

y=x(1:delta:L);

L1=length(y);

n1=0:L1-1;

Nfft=round(2.^round(log2(5*L)));                   

Xa=fft(x,Nfft);

range=0:(Nfft/4);

ff=range/Nfft/dt;

[H,W]=dtft(y,L);                                   

w1=W/2/pi/1000*fs;

y2=zeros(1,L);

for i=0:L1-1;

    y2(i*delta+1)=y(i+1);

end

fcut=2*(fs/2)/fsim;                                  

[b,a]=cheby2(9,60,fcut);                              

x1=delta*filter(b,a,y2);                                 

M=length(x1);

Nfft1=round(2.^round(log2(5*M)));                   

X=fft(x1,Nfft1);

range1=0:(Nfft1/4);

ff1=range1/Nfft1/dt;

subplot(223);plot(t,x1);grid;title('Xr(t)');xlabel('t');

subplot(224);plot(ff1/1000,abs(X(1:length(range1))));title('|Xr(j\omega)|');xlabel('kHz');

subplot(221);plot(t,x);grid;title('X(t)');xlabel('t');

subplot(222);plot(ff/1000,abs(Xa(1:length(range))));title('|X(j\omega)|');xlabel('kHz');

a,

b,                

 f0=6kHz

 f0=7kHz

 f0=9kHz

f0=10kHz

 f0=15kHz

 

第二篇：哈工程数字信号处理实验20xx版

数字信号处理实验报告（八）

一、实验名称：音频频谱分析仪设计与实现

二、实验原理：

1、信号频率、幅值和相位估计

(1)频率(周期)检测

对周期信号来说，可以用时域波形分析来确定信号的周期，也就是计算相邻的两个信号波峰的时间差、或过零点的时间差。这里采用过零点(ti)的时间差T(周期)。频率即为f = 1/T，由于能够求得多个T值(ti有多个)，故采用它们的平均值作为周期的估计值。

(2)幅值检测

在一个周期内，求出信号最大值ymax与最小值ymin的差的一半，即A = (ymax - ymin)/2，同样，也会求出多个A值，但第1个A值对应的ymax和ymin不是在一个周期内搜索得到的，故以除第1个以外的A值的平均作为幅值的估计值。

(3)相位检测

采用过零法，即通过判断与同频零相位信号过零点时刻，计算其时间差，然后换成相应的相位差。φ=2π(1-ti/T)，{x}表示x的小数部分，同样，以φ的平均值作为相位的估计值。

频率、幅值和相位估计的流程如图所示。

其中tin表示第n个过零点，yi为第i个采样点的值，Fs为采样频率。

2、数字信号统计量估计

(1) 峰值P的估计

在样本数据x中找出最大值与最小值，其差值为双峰值，双峰值的一半即为峰值。

P=0.5[max(yi)-min(yi)]

(2)均值估计

式中，N为样本容量，下同。

(3) 均方值估计

(4) 方差估计

2、频谱分析原理

时域分析只能反映信号的幅值随时间的变化情况，除单频率分量的简单波形外，很难明确提示信号的频率组成和各频率分量大小，而频谱分析能很好的解决此问题。

（1）DFT与FFT

对于给定的时域信号y，可以通过Fourier变换得到频域信息Y。Y可按下式计算

式中，N为样本容量，Δt = 1/Fs为采样间隔。

采样信号的频谱是一个连续的频谱，不可能计算出所有的点的值，故采用离散Fourier变换(DFT)，即

式中，Δf = Fs/N。但上式的计算效率很低，因为有大量的指数(等价于三角函数)运算，故实际中多采用快速Fourier变换(FFT)。其原理即是将重复的三角函数算计的中间结果保存起来，以减少重复三角函数计算带来的时间浪费。由于三角函数计算的重复量相当大，故FFT能极大地提高运算效率。

（2）频率、周期的估计

对于Y(kΔf)，如果当kΔf = 时，Y(kΔf)取最大值，则为频率的估计值，由于采样间隔的误差，也存在误差，其误差最大为Δf / 2。周期T=1/f。

从原理上可以看出，如果在标准信号中混有噪声，用上述方法仍能够精确地估计出原标准信号的频率和周期，这个将在下一章做出验证

3、频谱图

为了直观地表示信号的频率特性，工程上常常将Fourier变换的结果用图形的方式表示，即频谱图。

以频率f为横坐标，|Y(f)|为纵坐标，可以得到幅值谱；

以频率f为横坐标，arg Y(f)为纵坐标，可以得到相位谱；

以频率f为横坐标，Re Y(f)为纵坐标，可以得到实频谱；

以频率f为横坐标，Im Y(f)为纵坐标，可以得到虚频谱。

根据采样定理，只有频率不超过Fs/2的信号才能被正确采集，即Fourier变换的结果中频率大于Fs/2的部分是不正确的部分，故不在频谱图中显示。即横坐标f ∈[0, Fs/2]

4、模块划分

模块化就是把程序划分成独立命名且可独立访问的模块，每个模块完成一个子功能，把这些模块集成起来构成一个整体，可以完成指定的功能满足用户需求。根据人类解决一般问题的经验，如果一个问题由两个问题组合而成，那么它的复杂程度大于分别考虑每个问题时的复杂程度之和，也就是说把复杂的问题分解成许多容易解决的小问题，原来的问题也就容易解决了。这就是模块化的根据。

在模块划分时应遵循如下规则：改进软件结构提高模块独立性；模块规模应该适中；深度、宽度、扇出和扇入都应适当；模块的作用域应该在控制域之内；力争降低模块接口的复杂程度；设计单入口单出口的模块；模块功能应该可以预测。

三、实验内容：参考以上原理，查阅相关资料，构建交互界面，设计一个音频频谱分析仪，实现一下功能：

(1) 音频信号信号输入，从声卡输入、从WAV文件输入、从标准信号发生器输入；

(2) 信号波形分析，包括幅值、频率、周期、相位的估计，以及统计量峰值、均值、均方值和方差的计算；

(3) 信号频谱分析，频率、周期的估计，图形显示幅值谱、相位谱、实频谱、虚频谱和功率谱的曲线。

四、实验程序

                             正弦波

                              混叠正弦波

                         

                         方波

                          三角波

                          锯齿波

                                白噪声

function varargout = xty(varargin)

% XTY M-file for xty.fig

%      XTY, by itself, creates a new XTY or raises the existing

%      singleton*.

%

%      H = XTY returns the handle to a new XTY or the handle to

%      the existing singleton*.

%

%      XTY('CALLBACK',hObject,eventData,handles,...) calls the local

%      function named CALLBACK in XTY.M with the given input arguments.

%

%      XTY('Property','Value',...) creates a new XTY or raises the

%      existing singleton*.  Starting from the left, property value pairs are

%      applied to the GUI before guojing_OpeningFunction gets called.  An

%      unrecognized property name or invalid value makes property application

%      stop.  All inputs are passed to guojing_OpeningFcn via varargin.

%

%      *See GUI Options on GUIDE's Tools menu.  Choose "GUI allows only one

%      instance to run (singleton)".

%

% See also: GUIDE, GUIDATA, GUIHANDLES

% Edit the above text to modify the response to help xty

% Last Modified by GUIDE v2.5 02-Nov-2011 22:54:25

% Begin initialization code - DO NOT EDIT

gui_Singleton = 1;

gui_State = struct('gui_Name',       mfilename, ...

                   'gui_Singleton',  gui_Singleton, ...

                   'gui_OpeningFcn', @guojing_OpeningFcn, ...

                   'gui_OutputFcn',  @guojing_OutputFcn, ...

                   'gui_LayoutFcn',  [] , ...

                   'gui_Callback',   []);

if nargin && ischar(varargin{1})

    gui_State.gui_Callback = str2func(varargin{1});

end

if nargout

    [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});

else

    gui_mainfcn(gui_State, varargin{:});

end

% End initialization code - DO NOT EDIT

% --- Executes just before xty is made visible.

function guojing_OpeningFcn(hObject, eventdata, handles, varargin)

% This function has no output args, see OutputFcn.

% hObject    handle to figure

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% varargin   command line arguments to guojing (see VARARGIN)

% Choose default command line output for guojing

handles.output = hObject;

% Update handles structure

guidata(hObject, handles);

% UIWAIT makes xty wait for user response (see UIRESUME)

% uiwait(handles.figure1);

% --- Outputs from this function are returned to the command line.

function varargout = guojing_OutputFcn(hObject, eventdata, handles)

% varargout  cell array for returning output args (see VARARGOUT);

% hObject    handle to figure

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Get default command line output from handles structure

varargout{1} = handles.output;

% --- Executes on button press in soundcard.

function soundcard_Callback(hObject, eventdata, handles)

% hObject    handle to soundcard (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hint: get(hObject,'Value') returns toggle state of soundcard

set(findobj('Tag','recordtime'),'enable','on');

h=findobj('Tag','filename');

set(h,'enable','off');

h=findobj('Tag','freq');

set(h,'enable','off');

h=findobj('Tag','amp');

set(h,'enable','off');

h=findobj('Tag','phase');

set(h,'enable','off');

set(handles.channel,'enable','off');

set(handles.fileopen,'enable','off');

set(handles.gensig,'enable','off');

set(handles.wavetype,'enable','off');

set(handles.add,'enable','off');

set(handles.startrecord,'enable','on');

% --- Executes on button press in generator.

function generator_Callback(hObject, eventdata, handles)

% hObject    handle to generator (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hint: get(hObject,'Value') returns toggle state of generator

h=findobj('Tag','filename');

set(h,'enable','off');

h=findobj('Tag','freq');

set(h,'enable','on');

h=findobj('Tag','amp');

set(h,'enable','on');

h=findobj('Tag','phase');

set(h,'enable','on');

set(findobj('Tag','recordtime'),'enable','off');

set(handles.channel,'enable','off');

set(handles.fileopen,'enable','off');

set(handles.gensig,'enable','on');

set(handles.wavetype,'enable','on');

set(handles.add,'enable','on');

set(handles.startrecord,'enable','off');

function recordtime_Callback(hObject, eventdata, handles)

% hObject    handle to recordtime (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of recordtime as text

%        str2double(get(hObject,'String')) returns contents of recordtime as a double

% --- Executes during object creation, after setting all properties.

function recordtime_CreateFcn(hObject, eventdata, handles)

% hObject    handle to recordtime (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.

%       See ISPC and COMPUTER.

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor','white');

end

function filename_Callback(hObject, eventdata, handles)

% hObject    handle to filename (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of filename as text

%        str2double(get(hObject,'String')) returns contents of filename as a double

% --- Executes during object creation, after setting all properties.

function filename_CreateFcn(hObject, eventdata, handles)

% hObject    handle to filename (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.

%       See ISPC and COMPUTER.

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor','white');

end

% --- Executes on selection change in popupmenu1.

function popupmenu1_Callback(hObject, eventdata, handles)

% hObject    handle to popupmenu1 (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: contents = get(hObject,'String') returns popupmenu1 contents as cell array

%        contents{get(hObject,'Value')} returns selected item from popupmenu1

% --- Executes during object creation, after setting all properties.

function popupmenu1_CreateFcn(hObject, eventdata, handles)

% hObject    handle to popupmenu1 (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: popupmenu controls usually have a white background on Windows.

%       See ISPC and COMPUTER.

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor','white');

end

function freq_Callback(hObject, eventdata, handles)

% hObject    handle to freq (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of freq as text

%        str2double(get(hObject,'String')) returns contents of freq as a double

% --- Executes during object creation, after setting all properties.

function freq_CreateFcn(hObject, eventdata, handles)

% hObject    handle to freq (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.

%       See ISPC and COMPUTER.

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor','white');

end

function amp_Callback(hObject, eventdata, handles)

% hObject    handle to amp (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of amp as text

%        str2double(get(hObject,'String')) returns contents of amp as a double

% --- Executes during object creation, after setting all properties.

function amp_CreateFcn(hObject, eventdata, handles)

% hObject    handle to amp (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.

%       See ISPC and COMPUTER.

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor','white');

end

function phase_Callback(hObject, eventdata, handles)

% hObject    handle to phase (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of phase as text

%        str2double(get(hObject,'String')) returns contents of phase as a double

% --- Executes during object creation, after setting all properties.

function phase_CreateFcn(hObject, eventdata, handles)

% hObject    handle to phase (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.

%       See ISPC and COMPUTER.

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor','white');

end

% --- Executes on button press in startrecord.

function startrecord_Callback(hObject, eventdata, handles)

% hObject    handle to startrecord (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

Fs=str2double(get(findobj('Tag','samplerate'),'String'));

handles.y=wavrecord(str2double(get(findobj('Tag','recordtime'),'String'))*Fs, Fs,'double');

handles.inputtype=1;

guidata(hObject,handles);

plot(handles.time,handles.y);

title('WAVE');

ysize=size(handles.y)

set(handles.samplenum,'String',num2str(ysize(1)));

function channel_Callback(hObject, eventdata, handles)

% hObject    handle to channel (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of channel as text

%        str2double(get(hObject,'String')) returns contents of channel as a double

% --- Executes during object creation, after setting all properties.

function channel_CreateFcn(hObject, eventdata, handles)

% hObject    handle to channel (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.

%       See ISPC and COMPUTER.

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor','white');

end

% --- Executes on button press in fileopen.

function fileopen_Callback(hObject, eventdata, handles)

% hObject    handle to fileopen (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

temp=wavread(get(findobj('Tag','filename'),'String'));

channel=str2double(get(handles.channel,'String'));

handles.y=temp(:,channel);

handles.inputtype=2;

guidata(hObject,handles);

plot(handles.time,handles.y);

title('WAVE');

ysize=size(handles.y)

set(handles.samplenum,'String',num2str(ysize(1)));

% --- Executes on button press in add.

function add_Callback(hObject, eventdata, handles)

% hObject    handle to add (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hint: get(hObject,'Value') returns toggle state of add

% --- Executes on button press in gensig.

function gensig_Callback(hObject, eventdata, handles)

% hObject    handle to gensig (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

Fs=str2double(get(findobj('Tag','samplerate'),'String'));

N=str2double(get(findobj('Tag','samplenum'),'String'));

x=linspace(0,N/Fs,N);

soundtype=get(handles.wavetype,'Value');

frequency=str2double(get(handles.freq,'String'));

amp=str2double(get(handles.amp,'String'));

phase=str2double(get(handles.phase,'String'));

switch soundtype

    case 1

        y=amp*sin(2*pi*x*frequency+phase);

    case 2

        y=amp*sign(sin(2*pi*x*frequency+phase));

    case 3

        y=amp*sawtooth(2*pi*x*frequency+phase,0.5);

    case 4

        y=amp*sawtooth(2*pi*x*frequency+phase);

    case 5

        y=amp*(2*rand(size(x))-1);

    otherwise

        errordlg('Illegal wave type','Choose errer');

end

if get(handles.add,'Value')==0.0

    handles.y=y;

else

    handles.y=handles.y+y;

end

handles.inputtype=3;

guidata(hObject,handles);

plot(handles.time,handles.y);

title('WAVE');

axis([0 N -str2double(get(handles.amp,'String')) str2double(get(handles.amp,'String'))]);

% --- Executes on button press in WAVfile.

function WAVfile_Callback(hObject, eventdata, handles)

% hObject    handle to WAVfile (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hint: get(hObject,'Value') returns toggle state of WAVfile

h=findobj('Tag','filename');

set(h,'enable','on');

h=findobj('Tag','freq');

set(h,'enable','off');

h=findobj('Tag','amp');

set(h,'enable','off');

h=findobj('Tag','phase');

set(h,'enable','off');

set(findobj('Tag','recordtime'),'enable','off');

set(handles.channel,'enable','on');

set(handles.fileopen,'enable','on');

set(handles.gensig,'enable','off');

set(handles.wavetype,'enable','off');

set(handles.add,'enable','off');

set(handles.startrecord,'enable','off');

function samplerate_Callback(hObject, eventdata, handles)

% hObject    handle to samplerate (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of samplerate as text

%        str2double(get(hObject,'String')) returns contents of samplerate as a double

% --- Executes during object creation, after setting all properties.

function samplerate_CreateFcn(hObject, eventdata, handles)

% hObject    handle to samplerate (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.

%       See ISPC and COMPUTER.

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor','white');

end

function samplenum_Callback(hObject, eventdata, handles)

% hObject    handle to samplenum (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of samplenum as text

%        str2double(get(hObject,'String')) returns contents of samplenum as a double

% --- Executes during object creation, after setting all properties.

function samplenum_CreateFcn(hObject, eventdata, handles)

% hObject    handle to samplenum (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.

%       See ISPC and COMPUTER.

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor','white');

end

function pointfrom_Callback(hObject, eventdata, handles)

% hObject    handle to pointfrom (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of pointfrom as text

%        str2double(get(hObject,'String')) returns contents of pointfrom as a double

% --- Executes during object creation, after setting all properties.

function pointfrom_CreateFcn(hObject, eventdata, handles)

% hObject    handle to pointfrom (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.

%       See ISPC and COMPUTER.

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor','white');

end

function pointto_Callback(hObject, eventdata, handles)

% hObject    handle to pointto (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of pointto as text

%        str2double(get(hObject,'String')) returns contents of pointto as a double

% --- Executes during object creation, after setting all properties.

function pointto_CreateFcn(hObject, eventdata, handles)

% hObject    handle to pointto (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.

%       See ISPC and COMPUTER.

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor','white');

end

% --- Executes on button press in analyseall.

function analyseall_Callback(hObject, eventdata, handles)

% hObject    handle to analyseall (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

if get(hObject,'Value')==0.0

    set(handles.pointfrom,'Enable','on');

    set(handles.pointto,'Enable','on');

else

    set(handles.pointfrom,'String','1','Enable','off');

    set(handles.pointto,'String',get(handles.samplenum,'String'),'Enable','off');

end

% Hint: get(hObject,'Value') returns toggle state of analyseall

% --- Executes on button press in timeanalyse.

function timeanalyse_Callback(hObject, eventdata, handles)

% hObject    handle to timeanalyse (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

Fs=str2double(get(findobj('Tag','samplerate'),'String'));

N=str2double(get(findobj('Tag','samplenum'),'String'));

if handles.inputtype==0

        msgbox('No wave exist! Please choose a input type!');

        return;

end

%guo ling jian ce

n=1;

ymax=max([handles.y(1) handles.y(2)]);

ymin=min([handles.y(1) handles.y(2)]);

from=str2double(get(handles.pointfrom,'String'));

to=str2double(get(handles.pointto,'String'));

if from<1 | to-from<5;

    msgbox('Error range!');

    return;

end

for i=from+2:to-1;

    if handles.y(i-1)<0 & handles.y(i-2)<0 & handles.y(i)>=0 & handles.y(i+1)>0

        if handles.y(i)==0

            ti(n)=i;

        else

            ti(n)=i-handles.y(i)/(handles.y(i)-handles.y(i-1));

%             x1=i-1;

%             y1=handles.y(i-1);

%             x2=i;

%             y2=handles.y(i);

%             a=handles.y(i)-handles.y(i-1);

%             b=a*x1-y1;

%             ti(n)=b/a;

        end

        amp(n)=(ymax-ymin)/2;

        ymax=0;

        ymin=0;

        n=n+1;

    else

        if ymax<handles.y(i)

            ymax=handles.y(i);

        end

        if ymin>handles.y(i)

            ymin=handles.y(i);

        end

    end

end

n=n-1;

%freqence and periodicity

for i=1:n-1

    T(i)=ti(i+1)-ti(i);

end

freq=Fs/mean(T);

set(handles.outt,'String',1/freq);

set(handles.outfreq,'String',num2str(freq));

%amplitude

set(handles.outamp,'String',num2str(mean(amp(2:n-1))));

%phase

phase=2*pi*(1-(ti(1:n-1)-1)./T+floor((ti(1:n-1)-1)./T));

set(handles.outphase,'String',num2str(mean(phase)));

%peak

set(handles.outpeak,'String',(max(handles.y(from:to))-min(handles.y(from:to)))/2);

%mean

set(handles.outmean,'String',mean(handles.y(from:to)));

%meansquare

set(handles.outmeansquare,'String',mean(handles.y(from:to).^2));

%s

set(handles.outs,'String',std(handles.y(from:to))^2);

% --- Executes on button press in freqanalyse.

function freqanalyse_Callback(hObject, eventdata, handles)

% hObject    handle to freqanalyse (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

Fs=str2double(get(findobj('Tag','samplerate'),'String'));

N=str2double(get(findobj('Tag','samplenum'),'String'));

if handles.inputtype==0

        msgbox('No wave exist! Please choose a input type!');

        return;

end

from=str2double(get(handles.pointfrom,'String'));

to=str2double(get(handles.pointto,'String'));

sample=handles.y(from:to);

f=linspace(0,Fs/2,(to-from+1)/2);

Y=fft(sample,to-from+1);

[C,I]=max(abs(Y));

set(handles.foutt,'String',1/f(I));

set(handles.foutfreq,'String',f(I));

Y=Y(1:(to-from+1)/2);

plot(handles.plot1,f,2*sqrt(Y.*conj(Y)));

plot(handles.plot2,f,angle(Y));

plot(handles.plot3,f,real(Y));

plot(handles.plot4,f,imag(Y));

plot(handles.plot5,f,abs(Y).^2);

xlabel(handles.plot1,'freqency(Hz)');

xlabel(handles.plot2,'freqency(Hz)');

xlabel(handles.plot3,'freqency(Hz)');

xlabel(handles.plot4,'freqency(Hz)');

xlabel(handles.plot5,'freqency(Hz)');

ylabel(handles.plot1,'amplitude');

ylabel(handles.plot2,'phase(rad)');

ylabel(handles.plot3,'real');

ylabel(handles.plot4,'Imaginary');

ylabel(handles.plot5,'power');

function outt_Callback(hObject, eventdata, handles)

% hObject    handle to outt (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of outt as text

%        str2double(get(hObject,'String')) returns contents of outt as a double

% --- Executes during object creation, after setting all properties.

function outt_CreateFcn(hObject, eventdata, handles)

% hObject    handle to outt (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.

%       See ISPC and COMPUTER.

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor','white');

end

function outfreq_Callback(hObject, eventdata, handles)

% hObject    handle to outfreq (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of outfreq as text

%        str2double(get(hObject,'String')) returns contents of outfreq as a double

% --- Executes during object creation, after setting all properties.

function outfreq_CreateFcn(hObject, eventdata, handles)

% hObject    handle to outfreq (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.

%       See ISPC and COMPUTER.

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor','white');

end

function outamp_Callback(hObject, eventdata, handles)

% hObject    handle to outamp (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of outamp as text

%        str2double(get(hObject,'String')) returns contents of outamp as a double

% --- Executes during object creation, after setting all properties.

function outamp_CreateFcn(hObject, eventdata, handles)

% hObject    handle to outamp (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.

%       See ISPC and COMPUTER.

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor','white');

end

function outphase_Callback(hObject, eventdata, handles)

% hObject    handle to outphase (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of outphase as text

%        str2double(get(hObject,'String')) returns contents of outphase as a double

% --- Executes during object creation, after setting all properties.

function outphase_CreateFcn(hObject, eventdata, handles)

% hObject    handle to outphase (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.

%       See ISPC and COMPUTER.

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor','white');

end

function outpeak_Callback(hObject, eventdata, handles)

% hObject    handle to outpeak (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of outpeak as text

%        str2double(get(hObject,'String')) returns contents of outpeak as a double

% --- Executes during object creation, after setting all properties.

function outpeak_CreateFcn(hObject, eventdata, handles)

% hObject    handle to outpeak (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.

%       See ISPC and COMPUTER.

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor','white');

end

function outmean_Callback(hObject, eventdata, handles)

% hObject    handle to outmean (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of outmean as text

%        str2double(get(hObject,'String')) returns contents of outmean as a double

% --- Executes during object creation, after setting all properties.

function outmean_CreateFcn(hObject, eventdata, handles)

% hObject    handle to outmean (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.

%       See ISPC and COMPUTER.

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor','white');

end

function outmeansquare_Callback(hObject, eventdata, handles)

% hObject    handle to outmeansquare (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of outmeansquare as text

%        str2double(get(hObject,'String')) returns contents of outmeansquare as a double

% --- Executes during object creation, after setting all properties.

function outmeansquare_CreateFcn(hObject, eventdata, handles)

% hObject    handle to outmeansquare (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.

%       See ISPC and COMPUTER.

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor','white');

end

function outs_Callback(hObject, eventdata, handles)

% hObject    handle to outs (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of outs as text

%        str2double(get(hObject,'String')) returns contents of outs as a double

% --- Executes during object creation, after setting all properties.

function outs_CreateFcn(hObject, eventdata, handles)

% hObject    handle to outs (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.

%       See ISPC and COMPUTER.

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor','white');

end

function foutt_Callback(hObject, eventdata, handles)

% hObject    handle to foutt (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of foutt as text

%        str2double(get(hObject,'String')) returns contents of foutt as a double

% --- Executes during object creation, after setting all properties.

function foutt_CreateFcn(hObject, eventdata, handles)

% hObject    handle to foutt (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.

%       See ISPC and COMPUTER.

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor','white');

end

function foutfreq_Callback(hObject, eventdata, handles)

% hObject    handle to foutfreq (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of foutfreq as text

%        str2double(get(hObject,'String')) returns contents of foutfreq as a double

% --- Executes during object creation, after setting all properties.

function foutfreq_CreateFcn(hObject, eventdata, handles)

% hObject    handle to foutfreq (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.

%       See ISPC and COMPUTER.

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor','white');

end

% --- Executes on button press in play.

function play_Callback(hObject, eventdata, handles)

% hObject    handle to play (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

Fs=str2double(get(findobj('Tag','samplerate'),'String'));

wavplay(handles.y,Fs);

% --- Executes on selection change in wavetype.

function wavetype_Callback(hObject, eventdata, handles)

% hObject    handle to wavetype (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: contents = get(hObject,'String') returns wavetype contents as cell array

%        contents{get(hObject,'Value')} returns selected item from wavetype

% --- Executes during object creation, after setting all properties.

function wavetype_CreateFcn(hObject, eventdata, handles)

% hObject    handle to wavetype (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: popupmenu controls usually have a white background on Windows.

%       See ISPC and COMPUTER.

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor','white');

end

% --- Executes during object deletion, before destroying properties.

function add_DeleteFcn(hObject, eventdata, handles)

% hObject    handle to add (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% --- Executes during object creation, after setting all properties.

function time_CreateFcn(hObject, eventdata, handles)

% hObject    handle to time (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: place code in OpeningFcn to populate time

% --- Executes on slider movement.

function scale_Callback(hObject, eventdata, handles)

% hObject    handle to scale (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'Value') returns position of slider

%        get(hObject,'Min') and get(hObject,'Max') to determine range of slider

val=get(hObject,'value');

val=10^(val*5+1);

x=get(handles.xmove,'Value')*str2double(get(handles.samplenum,'String'));

axis(handles.time,[x val+x min(handles.y) max(handles.y)]);

% --- Executes during object creation, after setting all properties.

function scale_CreateFcn(hObject, eventdata, handles)

% hObject    handle to scale (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: slider controls usually have a light gray background.

if isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor',[.9 .9 .9]);

end

% --- Executes on slider movement.

function xmove_Callback(hObject, eventdata, handles)

% hObject    handle to xmove (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'Value') returns position of slider

%        get(hObject,'Min') and get(hObject,'Max') to determine range of slider

val=get(handles.scale,'value');

val=10^(val*5+1);

x=get(hObject,'Value')*str2double(get(handles.samplenum,'String'));

axis(handles.time,[x val+x min(handles.y) max(handles.y)]);

% --- Executes during object creation, after setting all properties.

function xmove_CreateFcn(hObject, eventdata, handles)

% hObject    handle to xmove (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: slider controls usually have a light gray background.

if isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor',[.9 .9 .9]);

end

% --- Executes on slider movement.

function scale2_Callback(hObject, eventdata, handles)

% hObject    handle to scale2 (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'Value') returns position of slider

%        get(hObject,'Min') and get(hObject,'Max') to determine range of slider

val=get(hObject,'value');

val=10^(val*5+1);

xlim(handles.plot1,[0 val]);

xlim(handles.plot2,[0 val]);

xlim(handles.plot3,[0 val]);

xlim(handles.plot4,[0 val]);

% --- Executes during object creation, after setting all properties.

function scale2_CreateFcn(hObject, eventdata, handles)

% hObject    handle to scale2 (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    empty - handles not created until after all CreateFcns called

% Hint: slider controls usually have a light gray background.

If isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))

    set(hObject,'BackgroundColor',[.9 .9 .9]);

end

结果分析：

   通过本次实验了解了gui的设计，学习了图形制作和程序设计，设计过程中有很多的不完美的地方，也有很多东西不懂，但也收获了很多！