filtdemo.m

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function [num,den]=filtdemo(action,s);
%FILTDEMO  Demonstrates filter design tools in the Signal Processing Toolbox.
%
%   To start the demo, type "filtdemo".
%
%   For more information, hit the "info" button once the demo is 
%   running.
%
%   Once you've designed a filter that you like,
%      [b,a] = filtdemo('getfilt');
%   gives you the filter coefficients.
%
%   See also CZTDEMO, MODDEMO, SOSDEMO.

%   Copyright (c) 1988-98 by The MathWorks, Inc.
%   $Revision: 1.27 $  $Date: 1997/12/02 18:36:51 $

%    T. Krauss, 11/15/93

% Possible actions and button callbacks:
%   initialize
%   changemethod
%   setFreqs
%   setRipples
%   dragRp
%   dragRs
%   dragWp
%   dragWs
%   setord
%   radio
%   design
%   axesredraw
%   info
%   closehelp
%   getfilt


if nargin<1,
    action='initialize';
end;

if strcmp(action,'initialize'),
    shh = get(0,'ShowHiddenHandles');
    set(0,'ShowHiddenHandles','on')
    figNumber=figure( ...
        'Name','Lowpass Filter Design Demo', ...
        'handlevisibility','callback',...
        'IntegerHandle','off',...
        'NumberTitle','off');

    %==================================
    % Set up the frequency response axes
    axes( ...
        'Units','normalized', ...
        'Position',[0.10 0.1 0.60 0.8], ...
        'XTick',[],'YTick',[], ...
        'Box','on');
    set(figNumber,'defaultaxesposition',[0.10 0.1 0.60 0.80])
    freqzHnd = subplot(1,1,1);
    set(gca, ...
        'Units','normalized', ...
        'Position',[0.10 0.1 0.60 0.8], ...
        'XTick',[],'YTick',[], ...
        'Box','on');

    %====================================
    % Information for all buttons (and menus)
    labelColor=[0.8 0.8 0.8];
    yInitPos=0.90;
    menutop=0.95;
    btnTop = 0.6;
    top=0.75;
    left=0.785;
    btnWid=0.175;
    btnHt=0.06;
    textHeight = 0.05;
    textWidth = 0.06;
    % Spacing between the button and the next command's label
    spacing=0.019;

    %====================================
    % The CONSOLE frame
    frmBorder=0.019; frmBottom=0.04; 
    frmHeight = 0.92; frmWidth = btnWid;
    yPos=frmBottom-frmBorder;
    frmPos=[left-frmBorder yPos frmWidth+2*frmBorder frmHeight+2*frmBorder];
    h=uicontrol( ...
        'Style','frame', ...
        'Units','normalized', ...
        'Position',frmPos, ...
	'BackgroundColor',[0.5 0.5 0.5]);

    %====================================
    % The Filter Design Routine Selection Menu
    btnNumber=1;
    yPos=menutop-(btnNumber-1)*(btnHt+spacing);
    btnPos=[left yPos-btnHt btnWid btnHt];
    labelStr='REMEZ|FIRLS|KAISER|BUTTER|CHEBY1|CHEBY2|ELLIP';
    callbackStr='filtdemo(''changemethod'');';
    methodHndl=uicontrol( ...
        'Style','popupmenu', ...
        'Units','normalized', ...
        'Position',btnPos, ...
        'String',labelStr, ...
        'Interruptible','on', ...
        'Callback',callbackStr);

    
    %===================================
    % Sampling frequency label 
    btnNumber=1;
    yPos=menutop-(btnNumber-1)*(btnHt+spacing);
    top = yPos - btnHt - spacing;
    labelWidth = frmWidth-textWidth-.01;
    labelBottom=top-textHeight;
    labelLeft = left;
    labelPos = [labelLeft labelBottom labelWidth textHeight];
    h = uicontrol( ...
        'Style','text', ...
        'Units','normalized', ...
	'Position',labelPos, ...
        'Horiz','left', ...
        'String','Fsamp', ...
        'Interruptible','off', ...
        'BackgroundColor',[0.5 0.5 0.5], ...
        'ForegroundColor','white');

    %===================================
    % Passband edge frequency label 
    btnNumber=2;
    yPos=menutop-(btnNumber-1)*(btnHt+spacing);
    top = yPos - btnHt - spacing;
    labelWidth = frmWidth-textWidth-.01;
    labelBottom=top-textHeight;
    labelLeft = left;
    labelPos = [labelLeft labelBottom labelWidth textHeight];
    h = uicontrol( ...
        'Style','text', ...
        'Units','normalized', ...
        'Position',labelPos, ...
        'Horiz','left', ...
        'String','Fpass', ...
        'Interruptible','off', ...
        'BackgroundColor',[0.5 0.5 0.5], ...
        'ForegroundColor','white');

    %===================================
    % Stopband edge frequency label and text field
    btnNumber=3;
    yPos=menutop-(btnNumber-1)*(btnHt+spacing);
    top = yPos - btnHt - spacing;
    labelWidth = frmWidth-textWidth-.01;
    labelBottom=top-textHeight;
    labelLeft = left;
    labelPos = [labelLeft labelBottom labelWidth textHeight];
    h = uicontrol( ...
        'Style','text', ...
        'Units','normalized', ...
	'Position',labelPos, ...
        'Horiz','left', ...
        'String','Fstop', ...
        'Interruptible','off', ...
        'BackgroundColor',[0.5 0.5 0.5], ...
        'ForegroundColor','white');
	% Text field
    textPos = [labelLeft+labelWidth-.015 labelBottom textWidth+.025 5*.85*textHeight];
    callbackStr = 'filtdemo(''setFreqs'')';
    str = sprintf('2000\n\n500\n\n600');
    mat = [2000; 500; 600];
    FreqsHndl = uicontrol( ...
        'Style','edit', ...
        'Units','normalized', ...
        'Position',textPos, ...
        'Max',2, ... % makes this a multiline edit object
        'Horiz','right', ...
        'Background','white', ...
        'Foreground','black', ...
        'String',str,'Userdata',mat, ...
        'callback',callbackStr);

    %===================================
    % passband ripple label
    btnNumber=4;
    yPos=menutop-(btnNumber-1)*(btnHt+spacing);
    top = yPos - btnHt - spacing;
    labelWidth = frmWidth-textWidth-.01;
    labelBottom=top-textHeight;
    labelLeft = left;
    labelPos = [labelLeft labelBottom labelWidth textHeight];
    h = uicontrol( ...
        'Style','text', ...
        'Units','normalized', ...
	'Position',labelPos, ...
        'Horiz','left', ...
        'String','Rpass', ...
        'Interruptible','off', ...
        'BackgroundColor',[0.5 0.5 0.5], ...
        'ForegroundColor','white');

    %===================================
    % stopband attenuation label and text field
    btnNumber=5;
    yPos=menutop-(btnNumber-1)*(btnHt+spacing);
    top = yPos - btnHt - spacing;
    labelWidth = frmWidth-textWidth-.01;
    labelBottom=top-textHeight;
    labelLeft = left;
    labelPos = [labelLeft labelBottom labelWidth textHeight];
    h = uicontrol( ...
        'Style','text', ...
        'Units','normalized', ...
	'Position',labelPos, ...
        'Horiz','left', ...
        'String','Rstop', ...
        'Interruptible','off', ...
        'BackgroundColor',[0.5 0.5 0.5], ...
        'ForegroundColor','white');
	% Text field
    textPos = [labelLeft+labelWidth labelBottom textWidth 3*.85*textHeight];
    textPos = [labelLeft+labelWidth-.015 labelBottom textWidth+.025 3*.85*textHeight];
    callbackStr = 'filtdemo(''setRipples'')';
    str = sprintf('3\n\n50');
    mat = [3;50];
    RipplesHndl = uicontrol( ...
        'Style','edit', ...
        'Units','normalized', ...
        'Position',textPos, ...
        'Max',2, ... % makes this a multiline edit object
        'Horiz','right', ...
        'Background','white', ...
        'Foreground','black', ...
        'String',str,'Userdata',mat, ...
        'callback',callbackStr);

    %====================================
    % Filter Order text label 
    btnNumber=6;
    yPos=menutop-(btnNumber-1)*(btnHt+spacing);
    top = yPos - btnHt - spacing;
    labelWidth = frmWidth-.01;
    labelBottom=top-textHeight;
    labelLeft = left;
    labelPos = [labelLeft labelBottom labelWidth textHeight];
    h = uicontrol( ...
        'Style','text', ...
        'Units','normalized', ...
	'Position',labelPos, ...
        'Horiz','center', ...
        'String','Order', ...
        'Interruptible','off', ...
        'BackgroundColor',[0.5 0.5 0.5], ...
        'ForegroundColor','white');

    %====================================
    % Estimate radio button and text field
    btnTop = labelBottom-spacing;
    btnNumber=8;
    yPos=menutop-(btnNumber-1)*(btnHt+spacing)+.02;
    labelStr='Auto:';
    callbackStr='filtdemo(''radio'',1)';
    btnPos=[left yPos-btnHt btnWid*.6 btnHt];
    btn1Hndl=uicontrol( ...
        'Style','radiobutton', ...
        'Units','normalized', ...
        'Position',btnPos, ...
        'String',labelStr, ...
        'value',1,'Userdata',1, ...
        'Callback',callbackStr);
    yPos=menutop-(btnNumber-1)*(btnHt+spacing) + .02;
    textPos=[left+btnWid*.62 yPos-btnHt btnWid*.45 btnHt];
    ord1Hndl = uicontrol( ...
        'Style','text', ...
        'Units','normalized', ...
        'Position',textPos, ...
        'String','22','Userdata',[22 -1]);
        %'Background',[.5 .5 .5], ...
        %'Foreground','white', ...

    %====================================
    % Specify radio button and text field
    btnTop = labelBottom-spacing;
    btnNumber=9;
    yPos=menutop-(btnNumber-1)*(btnHt+spacing)+.02;
    labelStr='Set:';
    callbackStr='filtdemo(''radio'',2);';
    btnPos=[left yPos-btnHt btnWid*.6 btnHt];
    btn2Hndl=uicontrol( ...
        'Style','radiobutton', ...
        'Units','normalized', ...
        'Position',btnPos, ...
        'String',labelStr, ...
        'value',0, ...
        'Callback',callbackStr);
    % btnTop = labelBottom-spacing;
    yPos=menutop-(btnNumber-1)*(btnHt+spacing) + .02;
    textPos=[left+btnWid*.62 yPos-btnHt btnWid*.45 btnHt];
    %top = yPos - btnHt - spacing;
    %labelWidth = frmWidth-textWidth-.01;
    %labelBottom=top-textHeight;
    %labelLeft = left;
    %textPos = [labelLeft+labelWidth labelBottom textWidth textHeight];
    callbackStr = 'filtdemo(''setord'')';
    ord2Hndl = uicontrol( ...
        'Style','edit', ...
        'Units','normalized', ...
        'Position',textPos, ...
        'Horiz','right', ...
        'Background','white', ...
        'Foreground','black', ...
        'String','22','Userdata',22, ...
        'callback',callbackStr);

    %====================================
    % View Popup - Menu 
    labelStr='Full view|Passband|Stopband';
    callbackStr='filtdemo(''axesredraw'');';
    viewHndl=uicontrol( ...
        'Style','popupmenu', ...
        'Units','normalized', ...
        'Position',[left frmBottom+2*(btnHt+spacing) btnWid btnHt], ...
        'String',labelStr, ...
        'Interruptible','on', ...
        'Callback',callbackStr);

    %====================================
    % The INFO button
    labelStr='Info';
    callbackStr='filtdemo(''info'')';
    helpHndl=uicontrol( ...
        'Style','pushbutton', ...
        'Units','normalized', ...
        'Position',[left frmBottom+btnHt+spacing btnWid btnHt], ...
        'String',labelStr, ...
        'Callback',callbackStr);

    %====================================
    % The CLOSE button
    labelStr='Close';
    callbackStr='close(gcf)';
    closeHndl=uicontrol( ...
        'Style','pushbutton', ...
        'Units','normalized', ...
        'Position',[left frmBottom btnWid btnHt], ...
        'String',labelStr, ...
        'Callback',callbackStr);

    fhndlList=[freqzHnd 0 0 FreqsHndl RipplesHndl ...
              0 viewHndl btn1Hndl btn2Hndl ord1Hndl ord2Hndl ...