fdutil.m

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    sb2 = fdspec('style','edit','position',10,'tag','sb2','format',fstr,...
                       'help','fdobjhelp');
    sb3 = fdspec('style','edit','position',11,'tag','sb3','format',fstr,...
                       'help','fdobjhelp');

    pbm1 = fdmeas('style','edit','position',5,'tag','pbm1','format',fstr,...
                       'help','fdobjhelp');
    pbm2 = fdmeas('style','edit','position',6,'tag','pbm2','format',fstr,...
                       'help','fdobjhelp');
    pbm3 = fdmeas('style','edit','position',7,'tag','pbm3','format',fstr,...
                       'help','fdobjhelp');
    sbm1 = fdmeas('style','edit','position',9,'tag','sbm1','format',fstr,...
                       'help','fdobjhelp');
    sbm2 = fdmeas('style','edit','position',10,'tag','sbm2','format',fstr,...
                       'help','fdobjhelp');
    sbm3 = fdmeas('style','edit','position',11,'tag','sbm3','format',fstr,...
                       'help','fdobjhelp');
    
    ax = fdax('tag','ax','title','Frequency Response',...
              'xlabel','Frequency',...
              'ylabel','Magnitude (dB)',...
              'help','fdobjhelp');
    
    co = get(0,'defaultaxescolororder');
    lo = get(0,'defaultaxeslinestyleorder');
    
    % response line needs to be at bottom of stacking order:
    Lresp = fdline('tag','response','erasemode','normal','color',co(1,:),...
                       'help','fdobjhelp');
                   
    L1 = fdline('tag','passband','color',co(min(3,size(co,1)),:),...
            'linewidth',2,...
            'help','fdobjhelp');

    L2 = fdline('tag','stopband','color',co(min(3,size(co,1)),:),...
            'linewidth',2,...
            'help','fdobjhelp');
            
    L3_1 = fdline('xdata',[0 0],'ydata',[-1000 1000],...
                   'tag','L3_1',...
                   'visible','off',...
                   'erasemode','xor',...
                   'affectlimits','off',...
                   'segmentdragmode',{'lr'},...
                   'segmentpointer',{'lrdrag'},...
                   'color',co(min(2,size(co,1)),:),...
                   'help','fdobjhelp');
                   
    L3_2 = fdline('xdata',[0 0],'ydata',[-1000 1000],...
                   'tag','L3_2',...
                   'visible','off',...
                   'erasemode','xor',...
                   'affectlimits','off',...
                   'segmentdragmode',{'lr'},...
                   'segmentpointer',{'lrdrag'},...
                   'color',co(min(2,size(co,1)),:),...
                   'help','fdobjhelp');

end
pbspecs = [pb1; pb2; pb3];
sbspecs = [sb1; sb2; sb3];
pbmeasures = [pbm1; pbm2; pbm3];
sbmeasures = [sbm1; sbm2; sbm3];


function changeToText(obj)
% changes FDSPEC or FDMEAS object's style to text
% sets position in case new style has different positioning
%  (which is the case when coming from edit on the Mac)
    bgcolor = get(0,'defaultuicontrolbackgroundcolor');
    for i = 1:length(obj) 
        set(obj(i),'style','text',...
                   'backgroundcolor',bgcolor)
        set(obj(i),'position',obj(i).position)
    end
    
function changeToEdit(obj)
% changes FDSPEC or FDMEAS object's style to edit
% sets position in case new style has different positioning
%  (which is the case when coming from text on the Mac)
    for i = 1:length(obj) 
        set(obj(i),'style','edit',...
                   'backgroundcolor','w')
        set(obj(i),'position',obj(i).position)
    end
    
function xlim = xlimpassband(type,Fs,f1,f2,f3,f4)
% returns passband xlimits 
switch type
case 1 % lowpass
    xlim = [0 f1];
case 2 % highpass
    xlim = [f2 Fs/2];
case 3 % bandpass
    xlim = [f2 f3];
case 4
    xlim = [0 Fs/2];
end
dxl = (xlim(2)-xlim(1))*.1;
xlim = inbounds(xlim+[-dxl/2 dxl/2],[0 Fs/2]);


function [ind,peaks] = findpeaks(y)
% FINDPEAKS  Find peaks in real vector.
%  ind = findpeaks(y) finds the indices (ind) which are
%  local maxima in the sequence y.  
%
%  [ind,peaks] = findpeaks(y) returns the value of the peaks at 
%  these locations, i.e. peaks=y(ind);

y = y(:)';

switch length(y)
case 0
    ind = [];
case 1
    ind = 1;
otherwise
    dy = diff(y);
    not_plateau_ind = find(dy~=0);
    ind = find( ([dy(not_plateau_ind) 0]<0) & ([0 dy(not_plateau_ind)]>0) );
    ind = not_plateau_ind(ind);
    if y(1)>y(2)
        ind = [1 ind];
    end
    if y(end-1)<y(end)
        ind = [ind length(y)];
    end
end

if nargout > 1
    peaks = y(ind);
end


function updateRanges(freq_ind,f1,f2,f3,f4)
% update ranges of frequency objects
% Inputs:
%   freq_ind - vector of indices of frequencies that have changed
%   f1,f2,f3,f4 - fdspec or fdmeas objects

    for i = 1:length(freq_ind)
        switch freq_ind(i)
        case 1
            r = get(f2,'range');
            set(f2,'range',[get(f1,'value') r(2)])
        case 2
            r = get(f1,'range');
            set(f1,'range',[r(1) get(f2,'value')])
            r = get(f3,'range');
            set(f3,'range',[get(f2,'value') r(2)])
        case 3
            r = get(f2,'range');
            set(f2,'range',[r(1) get(f3,'value')])
            r = get( f4,'range');
            set(f4,'range',[get(f3,'value') r(2)])
        case 4
            r = get(f3,'range');
            set(f3,'range',[r(1) get(f4,'value')])
        end
    end


function [continueFlag,str] = largeWarning(n,msg)
% If msg = 'motion' or 'up':
%    return an error string that the filter order is too large
% If msg = anything else:
%    issue a warning that filter order is very large 
%    and prompt user if they really want to do this
    str = { [num2str(n) ' is a very large filter order for']
            'this type of filter.  This may take a very long time'
            'and/or cause unpredictable results.  Are you sure you'
            'want to design this filter?'};
    if any(strcmp(msg,{'motion', 'up'}))
        continueFlag = 0;
        str = ['Filter order ' num2str(n) ' too large for this type of filter.'];
    else
        ans = questdlg(str,'Large Filter Order','Yes','No','No');
        continueFlag = strcmp(ans,'Yes');
        str = ['Filter order ' num2str(n) ' too large for this type of filter.'];
    end
    
    
function [xd1,xd2] = validateBands(xd1,xd2,type,f_ind,f,f1,f2,f3,f4,Fs)
% Function which makes sure frequency bands are legal, and fixes them if not
% Inputs:
%    xd1, xd2 - xdata of passband (xd1) and stopband (xd2) lines
%    type - filter type, 1=lp,2=hp,3=bp,4=bs
%    f_ind - index of frequency which has changed
%    f - frequency value vector, unnormalized
%    f1,f2,f3,f4 - fdspec or fdmeas objects - their values may be
%      changed during the execution of this function
%    Fs - sampling frequency

    if all(diff(f)>0)
        return
    end
    if type < 3
        f = f(1:2);
    end
    fobjs = [f1 f2 f3 f4];
    df = f(f_ind) - get(fobjs(f_ind),'lastvalue');
    [f,f_ind] = pushedges(f,f_ind,Fs,df);
    
    for ii = 1:length(f_ind)
        set(fobjs(f_ind(ii)),'value',f(f_ind(ii)))
    end
    
    f = [0 f Fs/2];
    switch type
    case 1   % lowpass
        xd1 = [f(1:2) NaN f(1:2)];
        xd2 = f(3:4);
    case 2   % highpass
        xd1 = [f(3:4) NaN f(3:4)];
        xd2 = f(1:2);
    case 3   % bandpass
        xd1 = [f(3:4) NaN f(3:4)];
        xd2 = [f(1:2) NaN f(5:6)];
    case 4   % bandstop
        xd1 = [f(1:2) NaN f(1:2) NaN f(5:6) NaN f(5:6)];
        xd2 = f(3:4);
    end

    
function [f,i] = pushedges(f,i,Fs,df)
% push band edges in frequency vector f, assuming edge i has changed    
% Inputs:
%    f - 2 or 4 element frequency band edge vector
%    i - index of changed element
%    Fs - sampling frequency
%    df - amount that f(i) has changed (so previous f(i) was f(i)-df)
%  Outputs:
%    f - new band edges, a row vector
%    i - indices of any band edges which have changed
    f_old = f(:);
    f = [0; f(:); Fs/2];
    j = i+1;
    sf = sign(df);
    N = length(f);
    while f(j)>0  &  f(j)<Fs/2 & sf ~= 0   % if sf=0 loop becomes infinite
        j = j + sf;
        if f(min(j,j-sf)) >= f(max(j,j - sf))   % need to push this band edge
            f(j) = f(j) + df;
            if ~rem(j,2) % j is even - push next band edge as well
                         % to keep transition band width constant
                f(j+sf) = f(j+sf) + df;
            end
        end
    end
    if (j>1) & (j<N) 
        if sf<0
            f = [linspace(0,f(i+1),i+1)'; f(i+2:end)];
        else
            f = [f(1:i); linspace(f(i+1),f(end),N-i)'];
        end
    end
    f = f(2:end-1);
    i = sort([i; find(f~=f_old)]);
    f = f(:)';
    
    
function [H,f] = chirpfreqz(num,den,fstart,fend,Fs,M)
%Compute frequency response of num,den using chirp z-transform
% Inputs:
%    num, den - filter coefficients
%    fstart, fend - starting and ending frequencies, in Hz
%    Fs - sampling frequency, in Hz 
%    M - number of points
% Outputs:
%    H - frequency response
%    f - frequencies = linspace(fstart,fend,M)

    delta_f = (fend - fstart)/(M-1)*2*pi/Fs;
    c = {M exp(-j*delta_f)  exp(j*fstart*2*pi/Fs)};
    H = czt(num,c{:})./czt(den,c{:});
    f = linspace(fstart,fend,M);
    
function H = dft(num,den,f,Fs)
%Compute frequency response of num,den using dft
% Inputs:
%    num, den - filter coefficients
%    f - frequency vector, in Hz
%    Fs - sampling frequency, in Hz 
% Outputs:
%    H - frequency response
    B = exp(-j*(f(:)*2*pi/Fs)*(0:length(num)-1))*num(:);
    A = exp(-j*(f(:)*2*pi/Fs)*(0:length(den)-1))*den(:);
    H = B./A;
    
function filt = updateFiltSpecs(filt)
%Updates filter structure (especially .specs field) from
%version 1.0 to version 2.0
    switch filt.specs.type
    case 1
    end

function [val,errstr] = fdvalidstr(str,complex,integer,range,inclusive);
% Check to see if string is valid given certain constraints.
% Inputs:
%   str - string as entered by user into edit box
%   complex - may the number entered be complex?  boolean, 1=true, 0=false
%   integer - must the string be an integer? boolean
%   range - 2 element real, range(1)<range(2), specifies interval for valid
%           values of val
%   inclusive - 2 element boolean vector, specifies whether min and max
%               in range argument are allowed as values
% Outputs:
%   val - numerical value of entered string, = [] if errstr is not empty
%   errstr - '' if value is valid, otherwise contains brief description
%             of why the str is bad.

    warnsave = warning;
    warning('off')  % turn off in case entry is empty or issues a warning
    val = evalin('base',str,'[]');
    validVal = 1;
    errstr = '';
    if all(size(val)==1)
        if ~complex & val~=real(val)
            validVal = 0;
            errstr = 'Sorry, this value must be real.';
        end
        if validVal & (integer & val~=round(val))
            validVal = 0;
            errstr = 'Sorry, this value must be an integer.';
        end
        if validVal & inclusive(1)
            validVal = validVal * (val>=range(1));
            if ~validVal
                errstr = rangeErrStr(range,inclusive);
            end
        elseif validVal & ~inclusive(1)
            validVal = validVal * (val>range(1));
            if ~validVal
                errstr = rangeErrStr(range,inclusive);
            end
        end
        if validVal & inclusive(2)
            validVal = validVal * (val<=range(2));
            if ~validVal
                errstr = rangeErrStr(range,inclusive);
            end
        elseif validVal & ~inclusive(2)
            validVal = validVal * (val<range(2));
            if ~validVal
                errstr = rangeErrStr(range,inclusive);
            end
        end
    else
        validVal = 0;
        errstr = sprintf(['Sorry, the value you entered either is' ...
                          ' the wrong size (it must be a scalar), or there' ...
                          ' was a problem evaluating it.']);
    end
    if ~isempty(errstr),
        val = [];
    end
    warning(warnsave)

function errstr = rangeErrStr(range,inclusive)
%rangeErrStr

    if all(inclusive == [1 1])
        errstr = sprintf('Sorry, this value must be at least %g and at most %g.',...
                                  range(1),range(2));
    elseif all(inclusive == [1 0])
        errstr = sprintf('Sorry, this value must be at least %g and less than %g.',...
                                  range(1),range(2));
    elseif all(inclusive == [0 1])
        errstr = sprintf('Sorry, this value must be greater than %g and at most %g.',...
                                  range(1),range(2));
    elseif all(inclusive == [0 0])
        errstr = sprintf('Sorry, this value must be greater than %g and less than %g.',...
                                  range(1),range(2));
    else
        error('inclusive value not set correctly')
    end
    

function setLines(module,L1,L2,setOrderFlag,type,f,Fs,...
                  minpass,maxpass,minstop,dragUpperPassband)
% NOTE: most modules must set setOrderFlag to 0 because it is possible
%  to drag L1 and L2 in set order mode
    if nargin<11
        % this input flag determines whether it is possible to
        % drag the upper passband line (desirable in fdkaiser, fdremez,
        % and fdfirls, but not for the 4 IIR routines)
        dragUpperPassband = 0;
    end
    switch type
    case 1   % lowpass
        set(L1,'xdata',[f(1:2) NaN f(1:2)]*Fs/2,...
               'ydata',[maxpass maxpass NaN minpass minpass])
        if ~setOrderFlag
            set(L1,...
               'vertexdragmode',{'none' 'lr' 'none' 'none' 'lr'},...
               'vertexdragcallback',...
                  {'' [module '(''L1drag'',1,2)'] '' '' ...
                  [module '(''L1drag'',1,5)']},...
               'vertexpointer',{'' 'lrdrag' '' '' 'lrdrag'})
        end
        set(L2,'xdata',[f(3:4)]*Fs/2,'ydata',[minstop minstop])
        if ~setOrderFlag
            set(L2,...
               'vertexdragmode',{'lr' 'none'},...
               'vertexdragcallback',...
                  {[module '(''L2drag'',1,1)'] ''},...
               'vertexpointer',{'lrdrag' ''})
        end
    case 2   % highpass
        set(L1,'xdata',[f(3:4) NaN f(3:4)]*Fs/2,...
               'ydata',[maxpass maxpass NaN minpass minpass ])
        if ~setOrderFlag
            set(L1,...
               'vertexdragmode',{'lr' 'none' 'none' 'lr' 'none'},...
               'vertexdragcallback',...
                  {[module '(''L1drag'',2,1)'] '' '' ...
                   [module '(''L1drag'',2,4)'] ''},...
               'vertexpointer',{'lrdrag' '' '' 'lrdrag' ''})
        end