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Analog Filter Design Toolbox

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Analog Filter Design Toolbox

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27 Dec 2005 (Updated )

GUI to design and simulate active (opamp) LP and HP Bessel, Butter, Cheby, and Elliptic filters.

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

% Last Modified by GUIDE v2.5 27-Dec-2003 12:04:25

% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @GuiListTransferFunction_OpeningFcn, ...
                   'gui_OutputFcn',  @GuiListTransferFunction_OutputFcn, ...
                   'gui_LayoutFcn',  [] , ...
                   'gui_Callback',   []);
if nargin & isstr(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 guiListTransferFunction is made visible.
function GuiListTransferFunction_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 guiListTransferFunction (see VARARGIN)

global strFilterObject
if isempty(strFilterObject)  % debug
    t = load('matlab.mat');
    strFilterObject = t.strFilterObject;
    disp('Debug mode')
end
strFilterObject = Utility_zpk(strFilterObject);

% create the numerator polynomial string
figure(hObject) %so if called a second time from main entry screen while this window preexists will write text to this window, not main screen
top = 45;  %pixels from bottom of uiax to bottom of numerator text
bot = 10;  %pixels from bottom of uiax to bottom of denomenator text
Font.FontUnits='points';
Font.FontSize=12;
Font.FontName='Arial';
hax = handles.uiax;
pixFigSize = get(hax,'position');
sNum=PolyString(strFilterObject.vZeros,'a');
hTextNum=text(pixFigSize(3)/2,top,sNum,Font,'Units','pixels','HorizontalAlignment','center');
handles.hTextNum = hTextNum;

% create the denomenator polynomial string
sDen=PolyString(strFilterObject.vPoles,'b');
hTextDen=text(pixFigSize(3)/2,bot,sDen,Font,'Units','pixels','HorizontalAlignment','center');
handles.hTextDen = hTextDen;

% move the dividing line
FixLineWidth(handles)

% add the text
PolyText(handles)

% and fix the status bar and title bar
sStatus=strFilterObject.sTitle;
set(handles.uitxStatus,'string','Close the window to return to the main screen')
set(handles.uiListTransferFunction,'Name',sStatus)

% Choose default command line output for guiListTransferFunction
handles.output = hObject;
guidata(hObject, handles);

% --- Outputs from this function are returned to the command line.
function varargout = GuiListTransferFunction_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 uirbPolynomial.
function uirbPolynomial_Callback(hObject, eventdata, handles)
global strFilterObject
set(handles.uirbPolynomial, 'Value', 1);
set(handles.uirbPoleZero, 'Value', 0);
set(handles.hTextNum,'string',PolyString(strFilterObject.vZeros*strFilterObject.fK,'a'))
set(handles.hTextDen,'string',PolyString(strFilterObject.vPoles,'b'))
FixLineWidth(handles)
PolyText(handles)

% --- Executes on button press in uirbPoleZero.
function uirbPoleZero_Callback(hObject, eventdata, handles)
global strFilterObject
set(handles.uirbPoleZero, 'Value', 1);
set(handles.uirbPolynomial, 'Value', 0);
set(handles.hTextNum,'string',RootString(strFilterObject.vZeros*strFilterObject.fK,'z'))
set(handles.hTextDen,'string',RootString(strFilterObject.vPoles,'p'))
FixLineWidth(handles)
RootText(handles)

%%%%%%%%%%%%%%%%%%%%%%%% Helper Functions %%%%%%%%%%%%%%%%%%%%%%%%%%%
% Returns a string in polynomial form
function sOut = PolyString(vRoots, sChar)
len=length(vRoots)+1;
sOut=[''];
for i=len:-1:3
   sOut = sprintf('%s + %s_%g s^%g',sOut,sChar,i-1,i-1);
end
if len>=2
    sOut = sprintf('%s + %s_1 s',sOut,sChar);
end
sOut = [sOut ' + ' sChar '_0'];
sOut = sOut(4:end);

% Returns a string in factored form
function sOut = RootString(vRoots, sChar)
sOut='';
if sChar=='z', sOut = 'k'; end
for i=1:length(vRoots)
   sOut = sprintf('%s (s-%s_%g)',sOut,sChar,i);
end

% Fixes the length of the divider line
function FixLineWidth(handles)
hTextDen = handles.hTextDen;
uiLine = handles.uiLine;
pixWidth = get(hTextDen,'Extent'); pixWidth = pixWidth(3);
pixPos = get(uiLine,'position');
pixMidPoint = pixPos(1)+pixPos(3)/2;
pixPos(3) = pixWidth;
pixPos(1) = pixMidPoint - pixWidth/2;
set(uiLine,'position',pixPos)

% Fills out the variable list in polynomial form
function PolyText(handles)
global strFilterObject
% fix k
set(handles.uiK,'visible','off');
% show numerator
vNum = poly(strFilterObject.vZeros)*strFilterObject.fK;
len = length(vNum);
for i=1:len
    h=findobj('Tag',['uia' num2str(i-1)]);
    set(h,'visible','on')
    set(h,'string',sprintf('a%g = %g',len-i,vNum(i)))
end
for i=length(vNum)+1:9
    h=findobj('Tag',['uia' num2str(i-1)]);
    set(h,'visible','off')
end    
% show denomenator
vDen = poly(strFilterObject.vPoles);
len = length(vDen);
for i=1:len
    h=findobj('Tag',['uib' num2str(i-1)]);
    set(h,'visible','on')
    set(h,'string',sprintf('b%g = %g',len-i,vDen(i)))
end
for i=length(vDen)+1:9
    h=findobj('Tag',['uib' num2str(i-1)]);
    set(h,'visible','off')
end
    
% Fills out the variable list in root factored form
function RootText(handles)
global strFilterObject
% show k
set(handles.uiK,'visible','on')
set(handles.uiK,'string',sprintf('k = %g',strFilterObject.fK))
% show zeros
vZeros = strFilterObject.vZeros;
for i=1:length(vZeros)
    h=findobj('Tag',['uia' num2str(i-1)]);
    set(h,'visible','on')
    fZero = vZeros(i);
    if isreal(fZero)
        set(h,'string',sprintf('z%g = %g',i,fZero))
    elseif imag(fZero)>0
        set(h,'string',sprintf('z%g = %g + j%g',i,real(fZero), imag(fZero))) 
    else
        set(h,'string',sprintf('z%g = %g -  j%g',i,real(fZero), -imag(fZero)))       
    end
end
for i=length(vZeros)+1:9
    h=findobj('Tag',['uia' num2str(i-1)]);
    set(h,'visible','off')
end
% show poles
vPoles = strFilterObject.vPoles;
for i=1:length(vPoles)
    h=findobj('Tag',['uib' num2str(i-1)]);
    set(h,'visible','on')
    fPole = vPoles(i);
    if isreal(fPole)
       set(h,'string',sprintf('p%g = %g',i,fPole))
   elseif imag(fPole)>0
       set(h,'string',sprintf('p%g = %g + j%g',i,real(fPole), imag(fPole)))   
   else
       set(h,'string',sprintf('p%g = %g -  j%g',i,real(fPole), -imag(fPole)))       
   end
end
for i=length(vPoles)+1:9
    h=findobj('Tag',['uib' num2str(i-1)]);
    set(h,'visible','off')
end

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