一、简介
1 设计原理
1.1 滤波器概念
1.2 数字滤波器的系统函数和差分方程
1.3 数字滤波器结构的表示
1.4 数字滤波器的分类
2.1 IIR滤波器与FIR滤波器的分析比较
2.2 FIR滤波器的原理
3 FIR滤波器的仿真步骤
二、源代码
function varargout = filter_2(varargin)
% FILTER_2 MATLAB code for filter_2.fig
% FILTER_2, by itself, creates a new FILTER_2 or raises the existing
% singleton*.
%
% H = FILTER_2 returns the handle to a new FILTER_2 or the handle to
% the existing singleton*.
%
% FILTER_2('CALLBACK',hObject,eventData,handles,...) calls the local
% function named CALLBACK in FILTER_2.M with the given input arguments.
%
% FILTER_2('Property','Value',...) creates a new FILTER_2 or raises the
% existing singleton*. Starting from the left, property value pairs are
% applied to the GUI before filter_2_OpeningFcn gets called. An
% unrecognized property name or invalid value makes property application
% stop. All inputs are passed to filter_2_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 filter_2
% Last Modified by GUIDE v2.5 16-May-2013 12:02:23
% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name', mfilename, ...
'gui_Singleton', gui_Singleton, ...
'gui_OpeningFcn', @filter_2_OpeningFcn, ...
'gui_OutputFcn', @filter_2_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 filter_2 is made visible.
function filter_2_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 filter_2 (see VARARGIN)
global response;
global analog;
global window1;
global digital;
global analog_choose;
response=1;
analog=1;
analog_choose=1;
window1=1;
digital=1;
%set(handles.function_value,'String','Butterworth');
%set(handles.method_value,'String','direct form');
set(handles.order,'Enable','off');
% Choose default command line output for filter_2
handles.output = hObject;
% Update handles structure
guidata(hObject, handles);
% UIWAIT makes filter_2 wait for user response (see UIRESUME)
% uiwait(handles.figure1);
% --- Outputs from this function are returned to the command line.
function varargout = filter_2_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 IIR_button.
function IIR_button_Callback(hObject, eventdata, handles)
% hObject handle to IIR_button (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
global analog_choose;
global response;
global analog;
if(get(hObject,'Value')==1) %当选中IIR时屏蔽FIR模块
set(handles.order_information,'String','order');
set(handles.FIR_button,'Value',0);
set(handles.filter_information,'String','IIR');
set(handles.window_function,'Enable','off');
set(handles.order,'Enable','off');
set(handles.view_window,'Enable','off');
set(handles.analog_filter,'Enable','on');
set(handles.Apass,'Enable','on');
set(handles.Astop,'Enable','on');
set(handles.order,'Enable','off');
set(handles.specify_order,'Enable','on'); set(handles.specify_order,'Value',0);%对阶数的处理
set(handles.custom_order,'Enable','on');set(handles.custom_order,'String','');
set(handles.min_order,'Enable','on');set(handles.min_order,'Value',0);
%get(handles.analog_method,'Value');
if( analog_choose==1)
set(handles.method_value,'String','direct form');
else
set(handles.method_value,'String','bilinear');
end
switch(analog)
case 1
set(handles.function_value,'String','Butterworth');
case 2
set(handles.function_value,'String','chebyshev1');
case 3
set(handles.function_value,'String','chebyshev2');
end
switch(response)
case 1
set(handles.type_information,'String','Lowpass');
case 2
set(handles.type_information,'String','Highpass');
case 3
set(handles.type_information,'String','Bandpass');
case 4
set(handles.type_information,'String','Bandstop');
end
else
set(handles.window_function,'Enable','on');
set(handles.order,'Enable','on');
set(handles.view_window,'Enable','on');
set(handles.order,'Enable','on');
end
% Hint: get(hObject,'Value') returns toggle state of IIR_button
% --- Executes on button press in FIR_button.
function FIR_button_Callback(hObject, eventdata, handles)
% hObject handle to FIR_button (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
global digital;
global response;
global window1;
if(get(hObject,'Value')==1) %当选中FIR时屏蔽IIR模块
set(handles.IIR_button,'Value',0);
set(handles.filter_information,'String','FIR');
set(handles.window_function,'Enable','on');
% set(handles.order,'Enable','on');
set(handles.view_window,'Enable','on');
set(handles.analog_filter,'Enable','off');
set(handles.Apass,'Enable','off');
set(handles.Astop,'Enable','off');
%set(handles.order,'Enable','on');
if(digital==2)%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%处理阶数
set(handles.specify_order,'Enable','off');
set(handles.custom_order,'Enable','off');
set(handles.min_order,'Enable','off');
set(handles.window_function,'Enable','off');
set(handles.view_window,'Enable','off');
set(handles.order_information,'String','sample')
set(handles.order,'Enable','on');
end
switch(response)
case 1
set(handles.type_information,'String','Lowpass');
case 2
set(handles.type_information,'String','Highpass');
case 3
set(handles.type_information,'String','Bandpass');
case 4
set(handles.type_information,'String','Bandstop');
end
if(digital==1)
set(handles.method_value,'String','window');
else
set(handles.method_value,'String','FSI');
end
switch(window1)
case 1
set(handles.function_value,'String','Hamming');
case 2
set(handles.function_value,'String','Blackman');
case 3
set(handles.function_value,'String','Hann');
case 4
set(handles.function_value,'String','Rectangular');
end
else
set(handles.analog_filter,'Enable','on');
set(handles.Apass,'Enable','on');
set(handles.Astop,'Enable','on');
set(handles.order,'Enable','off');
end
% Hint: get(hObject,'Value') returns toggle state of FIR_button
% --- If Enable == 'on', executes on mouse press in 5 pixel border.
% --- Otherwise, executes on mouse press in 5 pixel border or over filter_information.
function filter_information_ButtonDownFcn(hObject, eventdata, handles)
% hObject handle to filter_information (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
三、运行结果
四、备注
版本：2014a
