lowpassfilter.m

低通滤波器的仿真 GUI窗口实现 通过窗口中频率变换

function varargout = LowPassFilter(varargin)
% LOWPASSFILTER M-file for LowPassFilter.fig
%      LOWPASSFILTER, by itself, creates a new LOWPASSFILTER or raises the existing
%      singleton*.
%
%      H = LOWPASSFILTER returns the handle to a new LOWPASSFILTER or the handle to
%      the existing singleton*.
%
%      LOWPASSFILTER('CALLBACK',hObject,eventData,handles,...) calls the local
%      function named CALLBACK in LOWPASSFILTER.M with the given input arguments.
%
%      LOWPASSFILTER('Property','Value',...) creates a new LOWPASSFILTER or raises the
%      existing singleton*.  Starting from the left, property value pairs are
%      applied to the GUI before LowPassFilter_OpeningFunction gets called.  An
%      unrecognized property name or invalid value makes property application
%      stop.  All inputs are passed to LowPassFilter_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

% Copyright 2002-2003 The MathWorks, Inc.

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

% Last Modified by GUIDE v2.5 22-Dec-2008 23:00:26

% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @LowPassFilter_OpeningFcn, ...
                   'gui_OutputFcn',  @LowPassFilter_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 LowPassFilter is made visible.
function LowPassFilter_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 LowPassFilter (see VARARGIN)

% Choose default command line output for LowPassFilter
handles.output = hObject;

% Update handles structure
guidata(hObject, handles);

% UIWAIT makes LowPassFilter wait for user response (see UIRESUME)
% uiwait(handles.figure1);


% --- Outputs from this function are returned to the command line.
function varargout = LowPassFilter_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;



function f1_Callback(hObject, eventdata, handles)
% hObject    handle to f1 (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 f1 as text
%        str2double(get(hObject,'String')) returns contents of f1 as a double
handles.f1=str2double(get(hObject,'String'))
guidata(hObject,handles)


% --- Executes during object creation, after setting all properties.
function f1_CreateFcn(hObject, eventdata, handles)
% hObject    handle to f1 (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
    set(hObject,'BackgroundColor','white');
else
    set(hObject,'BackgroundColor',get(0,'defaultUicontrolBackgroundColor'));
end



function f2_Callback(hObject, eventdata, handles)
% hObject    handle to f2 (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 f2 as text
%        str2double(get(hObject,'String')) returns contents of f2 as a double

handles.f2=str2double(get(hObject,'String'))
guidata(hObject,handles)

% --- Executes during object creation, after setting all properties.
function f2_CreateFcn(hObject, eventdata, handles)
% hObject    handle to f2 (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
    set(hObject,'BackgroundColor','white');
else
    set(hObject,'BackgroundColor',get(0,'defaultUicontrolBackgroundColor'));
end



function Fp_Callback(hObject, eventdata, handles)
% hObject    handle to Fp (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 Fp as text
%        str2double(get(hObject,'String')) returns contents of Fp as a double
handles.Fp=str2double(get(hObject,'String'))
guidata(hObject,handles)

% --- Executes during object creation, after setting all properties.
function Fp_CreateFcn(hObject, eventdata, handles)
% hObject    handle to Fp (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
    set(hObject,'BackgroundColor','white');
else
    set(hObject,'BackgroundColor',get(0,'defaultUicontrolBackgroundColor'));
end



function Fs_Callback(hObject, eventdata, handles)
% hObject    handle to Fs (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 Fs as text
%        str2double(get(hObject,'String')) returns contents of Fs as a double
handles.Fs=str2double(get(hObject,'String'))
guidata(hObject,handles)

% --- Executes during object creation, after setting all properties.
function Fs_CreateFcn(hObject, eventdata, handles)
% hObject    handle to Fs (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
    set(hObject,'BackgroundColor','white');
else
    set(hObject,'BackgroundColor',get(0,'defaultUicontrolBackgroundColor'));
end



function Rp_Callback(hObject, eventdata, handles)
% hObject    handle to Rp (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 Rp as text
%        str2double(get(hObject,'String')) returns contents of Rp as a double
handles.Rp=str2double(get(hObject,'String'))
guidata(hObject,handles)

% --- Executes during object creation, after setting all properties.
function Rp_CreateFcn(hObject, eventdata, handles)
% hObject    handle to Rp (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
    set(hObject,'BackgroundColor','white');
else
    set(hObject,'BackgroundColor',get(0,'defaultUicontrolBackgroundColor'));
end



function Rs_Callback(hObject, eventdata, handles)
% hObject    handle to Rs (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 Rs as text
%        str2double(get(hObject,'String')) returns contents of Rs as a double
handles.Rs=str2double(get(hObject,'String'))
guidata(hObject,handles)

% --- Executes during object creation, after setting all properties.
function Rs_CreateFcn(hObject, eventdata, handles)
% hObject    handle to Rs (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
    set(hObject,'BackgroundColor','white');
else
    set(hObject,'BackgroundColor',get(0,'defaultUicontrolBackgroundColor'));
end


% --- 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)
F=8000;
n=0:200;
x=cos(handles.f1*2*pi*n/F)+cos(n*2*pi*handles.f2/F);
axes(handles.Signal)
plot(n,x);

[N,wc]=buttord(handles.Fp*2/F,handles.Fs*2/F,handles.Rp,handles.Rs);
[num,den]=butter(N,wc,'low');
y=filter(num,den,x);
axes(handles.LowPass)
plot(n,y)