pzfilterexpofn.m

非常好的数字处理教程

% This code borrows heavily from MAD polezero demonstration
function pzfilterexpo(action,datastruct)
    if nargin < 1
        action='init';
    end

	% Colormap isn't working as predicted

    name = mfilename;
    figname = [name(1:end-2) '_fig'];
    f=findobj('Tag',figname);
    handles = get(f,'UserData');

    switch action
		case 'help'
            display_help(figname);
        case 'init'
			setdefaults;
			reset(handles.specplot);
			reset(handles.timeplot);
			reset(handles.pz_plot);
			reset(handles.Hz_plot);
			handles.Fs = 44100;
			handles.npoints = 256;
			makePZPlot(handles);
			handles = makeHzPlot(handles);
			set(gcf,'KeyPressFcn','pzfilterexpofn keypressed');
		case 'loadsound'
			handles.audiodata = load_audiodata;
            handles.original = handles.audiodata;
            if ~isfield(handles.audiodata, 'filenamepath')
                return;
            end
            if (size(handles.audiodata.data,2) > 1)
                handles.audiodata.data = to_mono(handles.audiodata.data);
            end
            handles.Fs = handles.audiodata.Fs;
            contents = get(handles.fftsize,'String');
            fftsize = str2double(contents{get(handles.fftsize,'Value')});
            contents = get(handles.Window,'String');
            shape = contents{get(handles.Window,'Value')};
            [handles.spectrum, handles.bin, handles.st] = ...
                spectrogram(handles.audiodata, fftsize, shape);
            handles = makeTimePlot(handles);
            handles = makeSpecPlot(handles);
            handles = makeHzPlot(handles);
            handles = updateHzPlot(handles);
            linkedzoom([handles.timeplot, handles.specplot],'onx');
            place_header(f,handles);
            set(handles.freqzoom,'Value',1);
		case 'readinput'
			if isfield(datastruct,'polepos')
				handles.Fs = 44100;
				handles = makeHzPlot(handles);
                if isfield(datastruct, 'gain')
                    set(handles.gain,'String',num2str(datastruct.gain));
                end
				z = datastruct.zeropos; 
				% Remove zeros from 0
				z = z(find(z));
				zc = conj(z);
				elem = find(z == zc);
				if (elem > 0) 
					% Add just a bit so that the plot doesn't make them invisible
					mult = 0.00000;
					z = [z(1:elem-1); z(elem)+j*mult; z(elem)-j*mult; z(elem+1:end)];
					datastruct.zeropos = z;
				end 
				p = datastruct.polepos;
				% Remove poles from 0
				p = p(find(p));
				pc = conj(p);
				elem = find(p == pc);
				if (elem > 0)
					mult = 0.00000;
					p = [p(1:elem-1); p(elem)+j*mult; p(elem)-j*mult; p(elem+1:end)];
					datastruct.polepos = p;
				end

				for i=1:length(datastruct.zeropos)/2,
					x = real(datastruct.zeropos(i*2-1));
					y = imag(datastruct.zeropos(i*2-1));
					p1=text('Parent',handles.pz_plot,'Position',[x y],...
						'String','o','ButtonDownFcn','pzfilterexpofn selectzero',...
						'EraseMode','xor','Tag','Zero',...
						'HorizontalAlignment','center');
					if y ~= 0,
						p2=text('Parent',handles.pz_plot,'Position',[x -y],...
							'String','o','ButtonDownFcn','pzfilterexpofn selectzero',...
							'EraseMode','xor','Tag','Zero',...
							'HorizontalAlignment','center');
						set(p1,'UserData',p2);
						set(p2,'UserData',p1);
					end
				end
				for i=1:length(datastruct.polepos)/2,
					x = real(datastruct.polepos(i*2-1));
					y = imag(datastruct.polepos(i*2-1));
					p1=text('Parent',handles.pz_plot,'Position',[x y],...
						'String','x','ButtonDownFcn','pzfilterexpofn selectpole',...
						'EraseMode','xor','Tag','Pole',...
						'HorizontalAlignment','center');
					if y ~= 0,
						p2=text('Parent',handles.pz_plot,'Position',[x -y],...
							'String','x','ButtonDownFcn','pzfilterexpofn selectpole',...
							'EraseMode','xor','Tag','Pole',...
							'HorizontalAlignment','center');
						set(p1,'UserData',p2);
						set(p2,'UserData',p1);
					end
				end
				handles = updateHzPlot(handles);
			else
				handles.audiodata = datastruct;
				clear datastruct;
				if (size(handles.audiodata.data,2) > 1)
					handles.audiodata.data = to_mono(handles.audiodata.data);
				end
				handles.original = handles.audiodata;
				contents = get(handles.fftsize,'String');
				fftsize = str2double(contents{get(handles.fftsize,'Value')});
				contents = get(handles.Window,'String');
				shape = contents{get(handles.Window,'Value')};
				[handles.spectrum, handles.bin, handles.st] = ...
					spectrogram(handles.audiodata, fftsize, shape);
				handles = makeTimePlot(handles);
				handles = makeSpecPlot(handles);
				handles = makeHzPlot(handles);
				handles = updateHzPlot(handles);
            	linkedzoom([handles.timeplot, handles.specplot],'onx');
            	place_header(f,handles);
            	set(handles.freqzoom,'Value',1);
			end
        case {'playsound', 'playoriginal'}
            if isfield(handles, 'audiodata')
                times = get(handles.specplot,'XLim');
                switch action
                    case 'playsound'
                        audiodata = handles.audiodata;
                        button = handles.play;
                    case 'playoriginal'
                        audiodata = handles.original;
                        button = handles.playoriginal;
                end
                samples = floor(times*audiodata.Fs);
                if (samples(1) <= 0)
                   samples(1) = 1;
                end
                if (samples(2) > length(audiodata.data))
                   samples(2) = length(audiodata.data);
                end
                audiodata.data = audiodata.data(samples(1):samples(2));
                if (max(abs(audiodata.data)) > 1.0)
                    audiodata.data = normalize(audiodata.data);
                end
                play_audiodata(audiodata, button);
            end
		case {'db','inverse','interpolate','colormap','fftdisplay'}
			if isfield(handles, 'audiodata')
                updateSpecPlot(handles);
                set(handles.specplot,'XLim',get(handles.timeplot,'XLim'));
                pzfilterexpofn 'freqzoom';
            end
		case 'Hz_logf'
			if get(handles.Hz_logf,'Value')
				set(handles.Hz_plot,'XScale','log');
			else
				set(handles.Hz_plot,'XScale','linear');
			end
        case 'Hz_dB'
            axes(handles.Hz_plot);
			if get(handles.dB,'Value')
				set(handles.Hz_plot,'YLim',[-80 1]);
    			ylabel('Normalized Attenuation (dB)');
			else
				%set(handles.freq_plot,'YLim',[0 1.05]);
                %set(handles.freq_plot,'YLimMode','auto');
    			ylabel('Normalized Attenuation');
			end
			pzfilterexpofn 'plotfreqz'
		case {'fftsize','window'}
			if isfield(handles, 'audiodata')
                contents = get(handles.fftsize,'String');
                fftsize = str2double(contents{get(handles.fftsize,'Value')});
                contents = get(handles.Window,'String');
                shape = contents{get(handles.Window,'Value')};

                [handles.spectrum, handles.bin, handles.st] = ...
                    spectrogram(handles.audiodata, fftsize, shape);
                updateSpecPlot(handles);
                set(handles.specplot,'XLim',get(handles.timeplot,'XLim'));
                pzfilterexpofn 'freqzoom';
            end
		case 'normalize'
            if isfield(handles, 'audiodata')
				handles.audiodata.data = normalize(handles.audiodata.data);
				handles = makeTimePlot(handles);
                contents = get(handles.fftsize,'String');
                fftsize = str2double(contents{get(handles.fftsize,'Value')});
                contents = get(handles.Window,'String');
                shape = contents{get(handles.Window,'Value')};

                [handles.spectrum, handles.bin, handles.st] = ...
                    spectrogram(handles.audiodata, fftsize, shape);
                updateSpecPlot(handles);
                set(handles.specplot,'XLim',get(handles.timeplot,'XLim'));
                pzfilterexpofn 'freqzoom';
			end
		case 'freqzoom' 
            if isfield(handles,'audiodata')
                val = get(handles.freqzoom,'Value');
                if val == 0,
                    val = 0.001; 
                end
                Fs = handles.audiodata.Fs;
                set(handles.specplot,'YLim',[0 val*Fs/2])
            end
        case 'zoomreset'
            if isfield(handles,'audiodata')
                handles = makeTimePlot(handles);
                set(handles.specplot,'XLim',get(handles.timeplot,'XLim'));
                linkedzoom([handles.timeplot, handles.specplot],'onx');
            end
		case 'fourier'
			if isfield(handles,'audiodata')
				fourierexpogui(handles.audiodata);
			end
		case 'addzero'
			handles = add_coef(handles,'zero');
			pzfilterexpofn 'plotfreqz'
		case 'addpole'
			handles = add_coef(handles,'pole');
			pzfilterexpofn 'plotfreqz'
		case 'selectpole'
			handles = select_coef(handles,'pole');
		case 'selectzero'
			handles = select_coef(handles,'zero');
		case 'movepole'
			handles = move_coef(handles);
			pzfilterexpofn 'plotfreqz'
		case 'movezero'
			handles = move_coef(handles);
			pzfilterexpofn 'plotfreqz'
		case 'releaseobject'
			set(gcf,'WindowButtonMotionFcn','');
			set(gcf,'WindowButtonUpFcn','');
			%set([handles.currentcoef handles.partnercoef],'Selected','off');
			pzfilterexpofn 'plotfreqz'
		case 'plotfreqz'
			handles = updateHzPlot(handles);
		case 'loadvowel'
			axes(handles.pz_plot);
			cla;
			delete(findobj(gcf,'Selected','on'))
			makePZPlot(handles);
			bws=[0.03 0.07 0.1];    %formant freqs from Rabiner & Juang
			switch datastruct
				case 'beet'
					freqs=[270 2290 3010];
				case 'bit'
					freqs=[390 1990 2550];
				case 'bet'
					freqs=[530 1840 2480];
				case 'bat'
					freqs=[660 1720 2410];
				case 'bart'
					freqs=[730 1090 2440];
				case 'bort'
					freqs=[570 840 2410];
				case 'but'
					freqs=[440 1020 2240];
				case 'boot'
					freqs=[300 870 2240];
				case 'bert'
					freqs=[490 1350 1690];
				otherwise
			end
			% convert freqs and bws to PZ locations
			angs=2*pi*freqs/handles.Fs;
			for fr=1:length(freqs)
				[x,y]=pol2cart(angs(fr),1-bws(fr));
				p1=text('Parent',handles.pz_plot,'Position',[x y],...
					'String','x','ButtonDownFcn','pzfilterexpofn selectpole',...
					'EraseMode','xor','Tag','Pole','HorizontalAlignment','center');
				p2=text('Parent',handles.pz_plot,'Position',[x -y],...
					'String','x','ButtonDownFcn','pzfilterexpofn selectpole',...
					'EraseMode','xor','Tag','Pole','HorizontalAlignment','center');
				set(p1,'UserData',p2);
				set(p2,'UserData',p1);
			end
            handles = updateHzPlot(handles);
		case 'apply_filter'
            if isfield(handles, 'audiodata')
                handles = apply_filter(handles);
                contents = get(handles.fftsize,'String');
                fftsize = str2double(contents{get(handles.fftsize,'Value')});
                contents = get(handles.Window,'String');
                shape = contents{get(handles.Window,'Value')};
        
                [handles.spectrum, handles.bin, handles.st] = ...
                    spectrogram(handles.audiodata, fftsize, shape);
                updateSpecPlot(handles);
                Xlim = get(handles.timeplot,'XLim');
                handles = makeTimePlot(handles);
                set(handles.specplot,'XLim',Xlim);
                set(handles.timeplot,'XLim',Xlim);
                pzfilterexpofn 'freqzoom';
            end
		case 'keypressed'
			% if delete key is pressed, delete any selected object
				if double(get(gcf,'CurrentCharacter')) == 8
					delete(findobj(gcf,'Selected','on'))
				end
				pzfilterexpofn 'plotfreqz'
        case 'save'
            if isfield(handles.audiodata,'data')
				save_audiodata(handles.audiodata);
			end
		case 'undo'
            if isfield(handles,'audiodata')
			    handles = undo(handles);
			    updateSpecPlot(handles);
                Xlim = get(handles.timeplot,'XLim');
			    handles = makeTimePlot(handles);
                set(handles.specplot,'XLim',Xlim);
                set(handles.timeplot,'XLim',Xlim);
                pzfilterexpofn 'freqzoom';
            end
		case 'convexpo'
			polepos=findobj(handles.pz_plot,'Tag','Pole');
            zeropos=findobj(handles.pz_plot,'Tag','Zero');
            pp = [];
            zz = []; 
            for p=1:length(polepos) 
                ppos=get(polepos(p),'Position');
                pp(p)=complex(ppos(1),ppos(2));
            end 
            for z=1:length(zeropos) 
                zp=get(zeropos(z),'Position');
                zz(z)=complex(zp(1),zp(2));
            end
			[num,den]=zp2tf(zz',pp',1);
			data.impulse = filter(num, den,[1 zeros(1,99)]);
			convexpogui(data);
		case 'pzexpo'
			polepos=findobj(handles.pz_plot,'Tag','Pole');
            zeropos=findobj(handles.pz_plot,'Tag','Zero');