fdkaiser.m

matlabDigitalSigalProcess内有文件若干

function varargout = fdkaiser(varargin)
%fdkaiser  Kaiser Window FIR filter design Module for filtdes.

%   Author: T. Krauss
%   Copyright (c) 1988-98 by The MathWorks, Inc.
%   $Revision: 1.5 $

% Change this global to static when available:
%  following are common to several modules
global minOrdCheckbox bandpop order pbspecs sbspecs pbmeasures sbmeasures
global passframe stopframe passframe1 stopframe1
%  following static to fdkaiser
global f1 f2 f3 f4 Rp Rs Wn1 Wn2 Beta 
global Wn1m Wn2m Betam Rpm Rsm 
global order0 order1
global ax L1 L2 Lresp L3_1 L3_2
global Fs

switch varargin{1}
case 'init'

    filt = varargin{2};
    Fs = filt.Fs;
    [setOrderFlag_init, type_init, f_init, Rp_init, Rs_init, ...
      order_init, Wn_init, Beta_init] = initSpecs(filt);
         
    [minOrdCheckbox bandpop order pbspecs sbspecs ...
         pbmeasures sbmeasures passframe stopframe ...
         passframe1 stopframe1 ax Lresp L1 L2 order1 ...
         L3_1 L3_2] = fdutil('commonObjects');
    order0 = order;
    
    if ~strcmp(bandpop.userdata,'fdkaiser')
       % this module is not current
        bandpop.userdata = 'fdkaiser';
            
        minOrdCheckbox.callback = 'fdkaiser(''checkbox'')';
        bandpop.callback = 'fdkaiser(''newtype'')';         

        order0.callback = 'fdkaiser(''dirty'')';
                
        f3 = pbspecs(2);
        f4 = sbspecs(2);
        Rp = pbspecs(3);
        Rs = sbspecs(3);
        Wn1 = pbspecs(1);
        Wn2 = pbspecs(2);
        Beta = pbspecs(3);
        Wn1m = pbmeasures(1);
        Wn2m = pbmeasures(2);
        Betam = pbmeasures(3);

        Rpm = sbmeasures(1);
        Rsm = sbmeasures(2);
                
        set(ax,'title','Frequency Response',...
              'xlabel','Frequency',...
              'ylabel','Magnitude (dB)',...
              'ylim',[-150 10],'xlim',[0 Fs/2],...
              'xlimbound',[0 Fs/2]);

        sethelp

        set(Lresp,'buttondownfcn','fdkaiser(''LrespDown'')')
                       
        set(L1,'buttondownfcn','fdkaiser(''L1down'')',...
               'buttonupfcn','fdkaiser(''L1up'')');
    
        set(L2,'buttondownfcn','fdkaiser(''L2down'')',...
               'buttonupfcn','fdkaiser(''L2up'')');
               
        set(L3_1,'xdata',Wn_init([1 1]),...
                  'segmentdragcallback',{'fdkaiser(''3db_drag'',1)'},...
                  'buttondownfcn','fdkaiser(''3db_down'',1)',...
                  'buttonupfcn','fdkaiser(''L1up'')');
                  
        set(L3_2,'xdata',Wn_init([end end]),...
                  'segmentdragcallback',{'fdkaiser(''3db_drag'',2)'},...
                  'buttondownfcn','fdkaiser(''3db_down'',2)',...
                  'buttonupfcn','fdkaiser(''L1up'')');
    end  
    set(minOrdCheckbox,'visible','on')
    set(pbspecs(1),'visible','on')
    set(sbmeasures(3),'visible','off')
          
    fdkaiser('newfilt',setOrderFlag_init,type_init,f_init,Rp_init,...
               Rs_init,Wn_init,order_init,Beta_init)
               
    if setOrderFlag_init
    % set these fields since 'Apply' gets them from the specifications struc
    % to make the measurements
        filt.specs.fdkaiser.Rp = Rp_init;
        filt.specs.fdkaiser.Rs = Rs_init;
    end
    
    [filt, errstr] = fdutil('callModuleApply',...
                               'fdkaiser',filt,'');
    varargout{1} = filt;
    varargout{2} = errstr;

case 'apply'    

    filt = varargin{2};
    msg = varargin{3};
    if strcmp(msg,'motion') | strcmp(msg,'up')
        inputLine = varargin{4};
        if ~minOrdCheckbox.value & (isequal(inputLine,L1) | isequal(inputLine,L2))
            varargout{1} = filt;
            varargout{2} = '';
            return
        end
    end
    if strcmp(msg,'motion') & ~strcmp(get(Lresp,'erasemode'),'xor')
        Lresp.erasemode = 'xor';
        drawnow
    end
    
    % DESIGN FILTER!!!!
    type = bandpop.value;
    setOrderFlag = ~minOrdCheckbox.value;
    if ~setOrderFlag     % estimate order
        [n,Wn,beta_val] = estimateOrder(type,Rp.value,Rs.value,Fs,...
                 f1.value,f2.value,f3.value,f4.value);
        if ((type==2)|(type==4)) & rem(n,2)
            n = n + 1;
        end
    else
        n = order.value;
        Wn = Wn1.value * 2/Fs;
        if type > 2  % pass/stop
            Wn(2) = Wn2.value * 2/Fs;
        end
        beta_val = Beta.value;
    end
    
    % save specifications in specifications structure:
    specStruc.setOrderFlag = setOrderFlag;
    specStruc.type = type;
    if ~setOrderFlag
        f = getFrequencyValues(type,f1,f2,f3,f4,Fs);
        specStruc.f = f;
        specStruc.Rp = Rp.value;
        specStruc.Rs = Rs.value;
    else
        specStruc.f = [];  % place holder, will be defined by measureFilt
        specStruc.Rp = filt.specs.fdkaiser.Rp;
        specStruc.Rs = filt.specs.fdkaiser.Rs;
    end
    specStruc.Wn = Wn;
    specStruc.order = n;
    specStruc.Beta = beta_val;
                          
%     if ~setOrderFlag & isfield(filt.specs,'fdkaiser') & ...
%         isequal(specStruc.Wn,filt.specs.fdkaiser.Wn) ...
%         & isequal(specStruc.order,filt.specs.fdkaiser.order)
%         filt.specs.fdkaiser = specStruc;
%         varargout{1} = filt;
%         varargout{2} = '';
%         return
%     end
    if n>1000
        [continueFlag,errstr] = fdutil('largeWarning',n,msg);
        if ~continueFlag
            varargout{1} = filt;
            varargout{2} = errstr;
            return
        end
    end
    if ((type==2)|(type==4)) & rem(n,2)
        error('For highpass and bandstop filters, order must be even.')
    end
    
    % obtain Kaiser window:
    if isfield(filt.specs,'fdkaiser') & ...
       isfield(filt.specs.fdkaiser,'order') & ...
      ( (filt.specs.fdkaiser.order == n) ...
             & (filt.specs.fdkaiser.Beta == beta_val) )
        % recycle already computed window
        wind = filt.specs.fdkaiser.wind;
    else
        % compute and save window
        wind = kaiser(n+1,beta_val);
    end
    specStruc.wind = wind;
    
    % design filter:
    if type == 2
        [b,a] = fir1(n, Wn, 'high', wind, 'noscale');
    elseif type == 4
        [b,a] = fir1(n, Wn, 'stop', wind, 'noscale');
    else
        [b,a] = fir1(n, Wn, wind, 'noscale');
    end
        
    % compute frequency response:
    nfft = filtdes('nfft');
    [H,ff] = freqz(b,a,nfft,Fs);
    % avoid log of 0 at 0 and Fs/2:
    if H(1) == 0, H(1) = H(2); end
    if H(end) == 0, H(end) = H(end-1); end
    Hlog = 20*log10(abs(H(:)));
    set(Lresp,'xdata',ff,'ydata',Hlog);
    
    % make measurements:
    if ~ ((strcmp(msg,'motion') | strcmp(msg,'up')) & ~setOrderFlag ...
             & strcmp(get(order1,'visible'),'on') )  | ...
       (~setOrderFlag & (filt.specs.fdkaiser.type ~= type))
        objSetupFlag = 1;
    else
        objSetupFlag = 0;
    end
    
    [Rp,Rs,f1,f2,f3,f4,specStruc] = ...
      measureFilt(objSetupFlag,specStruc,Fs,order,order1,passframe1,stopframe1,ax,...
                  pbmeasures,sbmeasures,Rp,Rs,Wn1m,Wn2m,Betam,Rpm,Rsm,f1,f2,f3,f4,...
                  ff,Hlog,L1,L2);
                      
    if ~strcmp(msg,'motion')
        % if design is due to a drag operation, lines are already solid
        % so we can skip this step
        Lresp.linestyle = '-';
        L1.linestyle = '-';
        L2.linestyle = '-';
        set(L3_1,'linestyle','-')
        set(L3_2,'linestyle','-')
        if strcmp(L3_1.erasemode,'normal')
            warning('L3_1 erasemode is normal... why?')
            L3_1.erasemode = 'xor';
            L3_2.erasemode = 'xor';
        end
    end
    
    % alter filt fields:
    filt.tf.num = b;
    filt.tf.den = a;
    filt.specs.fdkaiser = specStruc;
    filt.zpk = [];  % clear out in case filtview has written these
    filt.ss = [];
    filt.sos = [];

    varargout{1} = filt;
    varargout{2} = '';
        
case 'revert'
    filt = filtdes('filt');
    oldtype = filt.specs.fdkaiser.type;
    % need to restore filter type
    setOrderFlag = filt.specs.fdkaiser.setOrderFlag;
    oldSetOrderFlag = ~minOrdCheckbox.value;
    f = filt.specs.fdkaiser.f;
    Rpass = filt.specs.fdkaiser.Rp;
    Rstop = filt.specs.fdkaiser.Rs;
    Wn = filt.specs.fdkaiser.Wn;
    N = filt.specs.fdkaiser.order;
    b = filt.specs.fdkaiser.Beta;
    fdkaiser('newfilt',setOrderFlag,oldtype,f,Rpass,Rstop,Wn,N,b)

    [Rp,Rs,f1,f2,f3,f4] = ...
      measureFilt(1,...
                  filt.specs.fdkaiser,Fs,order,order1,passframe1,stopframe1,ax,...
                  pbmeasures,sbmeasures,Rp,Rs,Wn1m,Wn2m,Betam,Rpm,Rsm,f1,f2,f3,f4,...
                  Lresp.xdata,Lresp.ydata,L1,L2);    
    
    Lresp.linestyle = '-';
    L1.linestyle = '-';
    L2.linestyle = '-';
    set(L3_1,'linestyle','-')
    set(L3_2,'linestyle','-')
    
    for i=1:3
        set(pbmeasures(i),'enable','on')
        set(sbmeasures(i),'enable','on')
    end
    set(order1,'enable','on')
    
case 'help'
    str = fdhelpstr('fdkaiser');
    varargout{1} = str{2};

case 'description'
    varargout{1} = 'Kaiser Window FIR';

case 'Fs'
% Sampling frequency has changed

%   The filter spec does not depend on the sampling frequency
    filt = varargin{2};
    varargout{1} = filt;
    
% update various lines and specifications:
    oldFs = varargin{3};
    Fs = filt.Fs;  % new Fs
    f1.value = f1.value*Fs/oldFs;
    f2.value = f2.value*Fs/oldFs;
    f3.value = f3.value*Fs/oldFs;
    f4.value = f4.value*Fs/oldFs;
    f1.range = f1.range*Fs/oldFs;
    f2.range = f2.range*Fs/oldFs;
    f3.range = f3.range*Fs/oldFs;
    f4.range = f4.range*Fs/oldFs;

    ax.xlimbound = [0 Fs/2];
    ax.xlim = ax.xlim*Fs/oldFs;
    ax.xlimpassband = ax.xlimpassband*Fs/oldFs;
    L1.xdata = L1.xdata*Fs/oldFs;
    L2.xdata = L2.xdata*Fs/oldFs;
    Lresp.xdata = Lresp.xdata*Fs/oldFs;
    L3_1.xdata = L3_1.xdata*Fs/oldFs;
    L3_2.xdata = L3_2.xdata*Fs/oldFs;
    
    if minOrdCheckbox.value
        Wn1m.value = Wn1m.value*Fs/oldFs;
        Wn2m.value = Wn2m.value*Fs/oldFs;
    elseif ~any(Wn1==[f1 f2 f3 f4])
        Wn1.value = Wn1.value*Fs/oldFs;
        Wn2.value = Wn2.value*Fs/oldFs;
        Wn1.range = Wn1.range*Fs/oldFs;
        Wn2.range = Wn2.range*Fs/oldFs;
    end
    
%---------------------------------------------------------------------
% -------- following cases are module specific --------- 
%---------------------------------------------------------------------

case 'dirty'
% fdkaiser('dirty')
% Callback of a spec ... to change appearance so user can
%  see that the specs and the currently designed filter
%  don't match
    if Lresp.linestyle ~= ':'
        Lresp.linestyle = ':';
        L1.linestyle = ':';
        L2.linestyle = ':';
        L3_1.linestyle = ':';
        L3_2.linestyle = ':';
    end
    for i=1:3
        set(pbmeasures(i),'enable','off')
        set(sbmeasures(i),'enable','off')
    end
    set(order1,'enable','off')

%---------------------------------------------------------------------
% fdkaiser('clean')
% opposite of 'dirty'
case 'clean'
    if Lresp.linestyle ~= '-'
        Lresp.linestyle = '-';
        L1.linestyle = '-';
        L2.linestyle = '-';
        L3_1.linestyle = '-';
        L3_2.linestyle = '-';
    end
    for i=1:3
        set(pbmeasures(i),'enable','on')
        set(sbmeasures(i),'enable','on')
    end
    set(order1,'enable','on')
    filtdes('setenable','off')
    
%---------------------------------------------------------------------
% fdkaiser('fchange',i)
%    Callback when frequency i has changed
%    Need to update ranges and lines L1, L2
% fdkaiser('fchange')
%    called w/o input i when a 3db frequency spec has 
%    changed (in case ~minOrdCheckbox.val==1)
case 'fchange'
    type = bandpop.value;
    if nargin == 1
    % a 3db freq spec has changed  (we are in set mode)
        
        if type >= 3
            Wn = [Wn1.value Wn2.value];
            set(L3_1,'xdata',Wn([1 1]))
            set(L3_2,'xdata',Wn([2 2]))
            Wn1.range = [0 Wn(2)];
            Wn2.range = [Wn(1) Fs/2];