fdremez.m

matlabDigitalSigalProcess内有文件若干

    type = varargin{2};
    ind = varargin{3};
    xd = L1.xdata;
    minspacing = Fs/500;
    switch type
    case 1  % lowpass
        newf1 = inbounds(xd(ind),[minspacing f2.value-minspacing]);
        xd([2 5]) = newf1;
        L1.xdata = xd;
        f1.value = newf1;
        i = 1;  % index of changed frequency
    case 2  % highpass
        newf2 = inbounds(xd(ind),[f1.value+minspacing Fs/2-minspacing]);
        xd([1 4]) = newf2;
        L1.xdata = xd;
        f2.value = newf2;
        i = 2;
    case 3  % bandpass
    % L1 xdata = [f2 f3 NaN f2 f3]
        if any(ind == [1 4])   % dragging f2
            newf2 = inbounds(xd(ind),[f1.value+minspacing f3.value-minspacing]);
            xd([1 4]) = newf2;
            L1.xdata = xd;
            f2.value = newf2;
            i = 2;
        else % dragging f3
            newf3 = inbounds(xd(ind),[f2.value+minspacing f4.value-minspacing]);
            xd([2 5]) = newf3;
            L1.xdata = xd;
            f3.value = newf3;
            i = 3;
        end
    case 4   % bandstop
    % L1 xdata = [0 f1 NaN 0 f1 NaN f4 Fs/2 NaN f4 Fs/2]
        if any(ind == [2 5])   % dragging f1
            newf1 = inbounds(xd(ind),[minspacing f2.value-minspacing]);
            xd([2 5]) = newf1;
            L1.xdata = xd;
            f1.value = newf1;
            i = 1;
        else % dragging f4
            newf4 = inbounds(xd(ind),[f3.value+minspacing Fs/2-minspacing]);
            xd([7 10]) = newf4;
            L1.xdata = xd;
            f4.value = newf4;
            i = 4;
        end
    end
    if type < 3
        f = {f1.value, f2.value};
    else
        f = {f1.value, f2.value, f3.value, f4.value};
    end
    ax.xlimPassband = fdutil('xlimpassband',type,Fs,f{:});
    
%---------------------------------------------------------------------
% fdremez('L2drag',type,ind)
%  drag callback of L2 - stopband line
%  Inputs:
%     type - band configuration 1==low, 2=high, 3=pass, 4=stop
%     ind - index of vertex being dragged
case 'L2drag'
    type = varargin{2};
    ind = varargin{3};
    xd = L2.xdata;
    minspacing = Fs/500;
    switch type
    case 1  % lowpass
        newf2 = inbounds(xd(ind),[f1.value+minspacing Fs/2-minspacing]);
        xd(1) = newf2;
        L2.xdata = xd;
        f2.value = newf2;
        i = 2;
    case 2  % highpass
        newf1 = inbounds(xd(ind),[minspacing f2.value-minspacing]);
        xd(2) = newf1;
        L2.xdata = xd;
        f1.value = newf1;
        i = 1;
    case 3  % bandpass
    % L2 xdata = [0 f1 NaN f4 Fs/2]
        if ind == 2   % dragging f1
            newf1 = inbounds(xd(ind),[minspacing f2.value-minspacing]);
            xd(2) = newf1;
            L2.xdata = xd;
            f1.value = newf1;
            i = 1;
        else % dragging f4
            newf4 = inbounds(xd(ind),[f3.value+minspacing Fs/2-minspacing]);
            xd(4) = newf4;
            L2.xdata = xd;
            f4.value = newf4;
            i = 4;
        end
    case 4   % bandstop
    % L2 xdata = [f2 f3]
        if ind == 1   % dragging f2
            newf2 = inbounds(xd(ind),[f1.value+minspacing f3.value-minspacing]);
            xd(1) = newf2;
            L2.xdata = xd;
            f2.value = newf2;
            i = 2;
        else % dragging f3
            newf3 = inbounds(xd(ind),[f2.value+minspacing f4.value-minspacing]);
            xd(2) = newf3;
            L2.xdata = xd;
            f3.value = newf3;
            i = 3;
        end
    end
    
%---------------------------------------------------------------------
% fdremez('Rpdrag',type,ind)
%  drag callback of L1 - passband line
%  Inputs:
%     type - band configuration 1==low, 2=high, 3=pass, 4=stop
%     ind - index of segment being dragged
case 'Rpdrag'
    type = varargin{2};
    ind = varargin{3};
    yd = L1.ydata;
    
    switch ind
    case {4,10}    % dragging lower line
        below = yd(ind);
        if below >= 0 
            below = -.00001;
        elseif below < -10
            below = -10;
        end
        dev = 1-10^(below/20);
        above = 20*log10(1+dev);
    case {1,7}    % dragging upper line
        above = yd(ind);
        if above > 10 
            above = 10;
        elseif above <= 0
            above = .00001;
        end
        dev = 10^(above/20)-1;
        below = 20*log10(1-dev);
    end
    
    newRp = above-below;
    if type ~= 4
    % 'ydata':[maxpass maxpass NaN minpass minpass]
        yd = [above above NaN below below];
    else
    % 'ydata': [ maxpass maxpass NaN minpass minpass NaN ...
    %                    maxpass maxpass NaN minpass minpass])
        yd = [above above NaN below below ...
               NaN above above NaN below below ];
    end
    L1.ydata = yd;
    ylim = [below above];
    dyl = (ylim(2)-ylim(1))*.15;
    ax.ylimPassband = ylim + [-dyl/2 dyl/2];
    if strcmp(get(wt1m,'visible'),'off')  % set order mode
        devs = [(10^(newRp/20)-1)/(10^(newRp/20)+1) 10^(-Rsm.value/20)];
        wt = [1 1]*max(devs)./devs;
        set(wt1,'value',wt(1))
        set(wt2,'value',wt(2))
    else
        Rp.value = newRp;
    end
%---------------------------------------------------------------------
% fdremez('Rsdrag',type,ind)
%  drag callback of L2 - stopband line
%  Inputs:
%     type - band configuration 1==low, 2=high, 3=pass, 4=stop
%     ind - index of segment being dragged
case 'Rsdrag'
    type = varargin{2};
    ind = varargin{3};
  
    yd = L2.ydata;
    newRs = -yd(ind);
    if newRs < 0
        newRs = 0;
    end
    switch type
    case {1,2,4}
        L2.ydata = [-newRs -newRs];
    case 3
        L2.ydata = [-newRs -newRs NaN -newRs -newRs];
    end
    if strcmp(get(wt1m,'visible'),'off')  % set order mode
        devs = [(10^(Rpm.value/20)-1)/(10^(Rpm.value/20)+1) 10^(-newRs/20)];
        wt = [1 1]*max(devs)./devs;
        set(wt1,'value',wt(1))
        set(wt2,'value',wt(2))
    else
        Rs.value = newRs;
    end
end  % of function switch-yard

%---------------------------------------------------------------------
% -------- LOCAL FUNCTIONS START HERE  --------- 
%---------------------------------------------------------------------

function sethelp
global minOrdCheckbox bandpop 
global passframe stopframe passframe1 stopframe1
global f1 f2 f3 f4 wt1 wt2 order Rp Rm pbspecs sbspecs
global Rpm Rsm wt1m wt2m
global ax L1 L2 Lresp
global Fs

% disp('setting help ... stub')


function [n,fo,mo,wt] = estimateOrder(type,Rp,Rs,Fs,f1,f2,f3,f4)
% [n,f,m,wt] = estimateOrder(type,Rp,Rs,Fs,f1,f2,f3,f4)
%   estimate filter order
%   takes the specifications as given by the input
%   parameters and estimates the order and weights
%   needed to meet those specifications.
% Inputs:
%  type - 1,2,3,4 specifies band configuration
%  Rp, Rs passband, stopband ripple
%  Fs - sampling frequency
%  f1,f2  first two frequencies in ascending order
%  f3,f4 only needed if type == 3 or 4, remaining frequencies
%    f1,f2,f3,f4 are normalized between 0 and 1
% Outputs:
%  n - filter order
%  f - filter band edges for remez
%  m - amplitudes for remez function
%  wt - filter band weights for remez function

%  
% compute deviations and estimate order
if type == 1    % low pass
    dev = [ (10^(Rp/20)-1)/(10^(Rp/20)+1)  10^(-Rs/20) ];
    f = [f1 f2];  m = [1 0];
elseif type == 2   % high pass
    dev = [ 10^(-Rs/20) (10^(Rp/20)-1)/(10^(Rp/20)+1)];
    f = [f1 f2];  m = [0 1];
elseif type == 3   % band pass
    dev = [ 10^(-Rs/20) (10^(Rp/20)-1)/(10^(Rp/20)+1) 10^(-Rs/20)];
    f = [f1 f2 f3 f4];  m = [0 1 0];
elseif type == 4   % band stop
    dev = [(10^(Rp/20)-1)/(10^(Rp/20)+1) ...
              10^(-Rs/20) (10^(Rp/20)-1)/(10^(Rp/20)+1)];
    f = [f1 f2 f3 f4];  m = [1 0 1];
end
[n,fo,mo,wt] = remezord(f,m,dev,Fs);
fo = fo(:)';   % make it a row
wt = wt(:)';   % make it a row
if type == 2 | type == 4   % highpass or bandstop
    if rem(n,2)==1   % if n is odd, must increase
        n = n+1;
    end
end
if n<3, n=3; end   % n must be at least 3 for remez
 
 
function yd = passbandlimits(Rp)
% return ydata = [minpass maxpass] of passband 
%   given Rp decibels of ripple
%   in passband (centered at 1 in linear scale)
    dev = (10^(Rp/20)-1)/(10^(Rp/20)+1);
    above = 20*log10(1+dev); below = 20*log10(1-dev);
    yd = [below above];


function [maxpass,minpass,minstop] = getMeasurements(ff,Hlog,type,...
                                          f1,f2,f3,f4);
    switch type
    case 1   % lowpass
        passInd = find(ff<=f1);
        stopInd = find(ff>=f2);
    case 2   % highpass
        stopInd = find(ff<=f1);
        passInd = find(ff>=f2);
    case 3   % bandpass
        stopInd = find((ff<=f1)|(ff>=f4));
        passInd = find((ff>=f2)&(ff<=f3));
    case 4   % bandstop
        passInd = find((ff<=f1)|(ff>=f4));
        stopInd = find((ff>=f2)&(ff<=f3));
    end
    maxpass = max(Hlog(passInd));
    minpass = min(Hlog(passInd));
    minstop = max(Hlog(stopInd));


function [setOrderFlag_init, type_init, f_init, Rp_init, Rs_init, ...
         order_init, wt_init] = initSpecs(filt)
%initSpecs   Initial specifications for remez filter, from
%            filt input
%Switches off of filt.currentModule and if it finds any of
% fdcheby1, fdcheby2, fdellip, fdbutter, fdfirls, or fdkaiser
% retains the type, order, band edge, and any other relevant
% parameters

    % first define default values
    setOrderFlag_init = 0;   % by default, estimate order 
    type_init = 1;  % 1=lowpass, 2=highpass, 3=bandpass, 4=bandstop
    f_init = [0 .1 .15 .5];
    Rp_init = 3;
    Rs_init = 20;
    order_init = 30;
    wt_init = [1 1];
    switch filt.specs.currentModule
    case {'fdcheby1','fdcheby2','fdellip','fdbutter','fdkaiser','fdfirls'}
        s = eval(['filt.specs.' filt.specs.currentModule]);
        setOrderFlag_init = s.setOrderFlag;
        type_init = s.type;
        f_init = s.f;
        Rp_init = s.Rp;
        Rs_init = s.Rs;
        order_init = s.order;
        
        if strcmp(filt.specs.currentModule,'fdfirls')
            wt_init = s.wt;
        else
            devs = [(10^(s.Rp/20)-1)/(10^(s.Rp/20)+1) 10^(-s.Rs/20)];
            switch s.type
            case 3
                devs = devs([2 1 2]);
            case 4
                devs = devs([1 2 1]);
            end
            wt_init = ones(size(devs))*max(devs)./devs;
        end
        if any(strcmp(filt.specs.currentModule,...
                 {'fdcheby1','fdcheby2','fdellip','fdbutter'}))
            order_init = order_init*10;  %  FIR filters are much higher order
                                         %  than IIR
        end
    
    case 'fdremez'
        if isfield(filt.specs,'fdremez')
            setOrderFlag_init = filt.specs.fdremez.setOrderFlag;
            type_init = filt.specs.fdremez.type;
            f_init = filt.specs.fdremez.f;
            Rp_init = filt.specs.fdremez.Rp;
            Rs_init = filt.specs.fdremez.Rs;
            order_init = filt.specs.fdremez.order;
            wt_init = filt.specs.fdremez.wt;
        end
    end