bodeplotgui.m

在Matlab中可以使用的波特图的例子源码

   % Get string representations of numerator and denominator
   nStr=poly2str(n,'s');
   dStr=poly2str(d,'s');

   % Find length of strings.
   LnStr=length(nStr);
   LdStr=length(dStr);

   if LnStr>LdStr,
      %the numerator is longer than denominator string, so pad denominator.
      n=LnStr;              %n is the length of the longer string.
      nStr=['     ' nStr];   %add spaces for characters at beginning of divStr.
      dStr=['     ' blanks(floor((LnStr-LdStr)/2)) dStr];  %pad denominator.
   else
      %the demoninator is longer than numerator, pad numerator.
      n=LdStr;
      nStr=['     ' blanks(floor((LdStr-LnStr)/2)) nStr];
      dStr=['     ' dStr];
   end

   divStr=[];
   for i=1:n,
      divStr=[divStr '-'];
   end
   divStr=['H(s) = ' divStr];

   set(handles.TransferFunctionText,'String',strvcat(nStr,divStr,dStr));

   %Change type font and size.
   set(handles.TransferFunctionText,'FontName','Courier New')
   %set(handles.TransferFunctionText,'FontSize',10)

   guidata(handles.AsymBodePlot, handles);  %save changes to handles.
end
% ------------------End of function BodePlotDispTF -------------------


% --------------------------------------------------------------------
function BodePlotLegend(handles)
   %This function creates the legends for the Bode plot being displayed.
   %It also makes four changes to the "handles" structure.
   %   1)  It updates the array "IncElem" that holds the indices that determine
   %       which elements are included in the Bode plot.
   %   2)  It updates the sring array "IncStr" that hold the description of
   %       each included elements.
   %   3)  Updates ExcElem that holds indices of excluded elements.
   %   4)  Updates ExcStr that hold descriptions of excluded elements.

   %Load the terms and the plotting strings into local variables for convenience.
   Terms=handles.Terms;

   axes(handles.LegendPlot);   %Set axes to the legend widow,
   cla;                        %   and clear it.
   Xleg=[0 0.2];               %Xleg holds start and end of line segment for legend.
   XlegText=0.25;              %XlegText is location of text.
   FntSz=8;                    %Font Size of text.

   y=1-1/(length(Terms)+6);    %Vertical location of first text item
   plot(Xleg,[y y],...
      'Color',handles.exactColor,...
      'LineWidth',handles.LnWdth/2);   %Plot line for legend.
   text(XlegText,y,'Exact Bode Plot','FontSize',FntSz);        %Place text
   hold on;

   if (get(handles.ShowAsymptoticCheckBox,'Value')~=0),
      y=1-2/(length(Terms)+6);    %Vertical location of second item
      plot(Xleg,[y y],...
         'Color',handles.exactColor,...
         'LineStyle',':',...
         'LineWidth',handles.LnWdth);   %Plot line for legend.
      text(XlegText,y,'Asymptotic Plot','FontSize',FntSz);               %Place text
   end

   y=1-3/(length(Terms)+6);     %Vertical location of third item.
   plot(Xleg,[y y],...                %Line.
      'Color',handles.zrefColor,...
      'LineWidth',2);
   text(XlegText,y,'Zero Value (for reference only)','FontSize',FntSz); %Text.

   IncElem=[]; %The indices of elements to be included in plot.
   ExcElem=[]; %The indices of elements to be excluded from plot.
   IncStr='';  %An array of strings describing included elements.
   ExcStr='';  %An array of strings describing excluded elements.

   %These variables are used as local counters later.  Here they are initialized.
   i1=1;
   i2=1;

   for i=1:length(Terms),          %For each term,

      %Tv is a local variable representing the pole location.  It is used solely
      %   for convenience.
      Tv=Terms(i).value;
      %Tm is a local variable representing the pole multiplicity.  It is used solely
      %   for convenience.
      Tm=Terms(i).multiplicity;
      %S2 is a blank string to be added to later in the loop.
      S2='';

      %The next section of code ("switch" statement) plus a few lines, creates
      %a string that describes the pole or zero, its location, muliplicity...
      %The variable "DescStr" hold a Descriptive String for the pole or zero. The
      %string "S2" is a Second String that holds additional information (if needed)
      switch Terms(i).type,
         case 'Constant',
            %If the term is a consant, print its value in a string.
            DescStr=sprintf('Constant = %0.2g (%0.2g dB)',Tv,20*log10(Tv));
         case 'RealPole',
            %If the term is a real pole, print its value in string.
            DescStr=sprintf('Real Pole at %0.2g',Tv);
         case 'RealZero',
            %If the term is a real zero, print its value in string.
            DescStr=sprintf('Real Zero at %0.2g',Tv);
            if real(Tv)>0,
               DescStr=[DescStr ' RHP (Non-min phase)'];
            end;
         case 'ComplexPole',
            %If the term is a complex pole, print its value in string.
            %However, do this in terms of natural frequency and damping, as
            %well as the actual location of the pole (in S2).
            wn=abs(Tv);
            theta=atan(abs(imag(Tv)/real(Tv)));
            zeta=cos(theta);
            DescStr=sprintf('Complex Pole at wn=%0.2g, zeta=%0.2g',wn,zeta);
            if (zeta < (1/sqrt(2))),  %peaking only if zeta<0.707
               S2=sprintf('(%0.2g +/- %0.2gj)  Circle shows peak height.',real(Tv),imag(Tv));
            else
               S2=sprintf('(%0.2g +/- %0.2gj)  (no peaking, zeta<0.707)',real(Tv),imag(Tv));
            end
         case 'ComplexZero',
            %If the term is a complex zero, print its value in string.
            %However, do this in terms of natural frequency and damping, as
            %well as the actual location of the zero (in S2).
            %Also note if it is a non-minimum phase zero.
            wn=abs(Tv);
            theta=atan(abs(imag(Tv)/real(Tv)));
            zeta=cos(theta);
            DescStr=sprintf('Complex Zero at wn=%0.2g, zeta=%0.2g',wn,zeta);
            if real(Tv)>0,
               DescStr=[DescStr ' (RHP, Non-min phase)'];
            end;
            if (zeta < (1/sqrt(2))),  %peaking only if zeta<0.707
               S2=sprintf('(%0.2g +/- %0.2gj)  Circle shows peak height.',real(Tv),imag(Tv));
            else
               S2=sprintf('(%0.2g +/- %0.2gj)  (no peaking, zeta<0.707)',real(Tv),imag(Tv));
            end
         case 'OriginPole',
            %If pole is at origin, not this.
            DescStr=sprintf('Pole at origin');
         case 'OriginZero',
            %If zero is at origin, not this.
            DescStr=sprintf('Zero at origin');
      end
      %If multiplicity is greater than one, not this as well.
      if Tm>1,
         DescStr=[DescStr sprintf(', mult=%d',Tm)];
      end

      %At this point we have a string (in "DescStr" and "S2").
      if Terms(i).display,    %If the term is to be included in plot....
         IncStr=strvcat(IncStr,DescStr); %Add the Desriptive String to IncStr
         IncElem(i1)=i;  %Add the appropriate index to the Included Elements list.
         i1=i1+1;        %Increment the index counter
         y=1-(i1+2)/(length(Terms)+6);   %Calculate the vertical position.
         plot(Xleg,[y y],...             %Plot the line.
            'LineWidth',handles.LnWdth,...
            'LineStyle',GetLineStyle(i,handles),...
            'Color',GetLineColor(i,handles));
         text(XlegText,y,strvcat(DescStr,S2),'FontSize',FntSz);  %Add the text.
      else    %The term is *not* to be included in plot, so...
         ExcStr=strvcat(ExcStr,DescStr); %Add its Desriptive String to ExcStr
         ExcElem(i2)=i;  %Add the appropriate index to the Excluded Elements list.
         i2=i2+1;        %Increment the index counter.
      end
   end
   hold off;
   %Get rid of ticks around plot.
   axis([0 1 0 1]);
   set(gca,'Xtick',[]);
   set(gca,'Ytick',[]);

   %At this point the legend is completed.  Next we will make up the strings
   %for the boxes that separately list included and excluded elements.

   IncStr=strvcat(IncStr,' ');         %Add a blank line to IncStr.
   IncStr=strvcat(IncStr,'-------');   %Add a series of dashes.
   %If there are any included elements, we can click on box to exclude it.
   if i1~=1
      IncStr=strvcat(IncStr,'Select element to exclude from plot');
   end

   ExcStr=strvcat(ExcStr,' ');         %Add a blank line to ExcStr
   ExcStr=strvcat(ExcStr,'-------');   %Add a series of dashes.
   %If there are any excluded elements, we can click on box to include it.
   if i2~=1
      ExcStr=strvcat(ExcStr,'Select element to include in plot');
   end

   %Set the strings for included and excluded elements.
   set(handles.IncludedElements,'String',IncStr);
   set(handles.ExcludedElements,'String',ExcStr);

   %Change the arrays holding included and excluded elements in the handles array.
   handles.IncElem=IncElem;
   handles.ExcElem=ExcElem;

   guidata(handles.AsymBodePlot, handles);  %save changes to handles.
end
% ------------------End of function BodePlotLegend --------


% --------------------------------------------------------------------
% --- Executes during object creation, after setting all properties.
function LineWidth_CreateFcn(hObject, eventdata, handles)
   % hObject    handle to LineWidth (see GCBO)
   % eventdata  reserved - to be defined in a future version of MATLAB
   % handles    empty - handles not created until after all CreateFcns called
   if ispc
      set(hObject,'BackgroundColor','white');
   else
      set(hObject,'BackgroundColor',get(0,'defaultUicontrolBackgroundColor'));
   end
end
% ------------------End of function BodePlotLegend --------


% --------------------------------------------------------------------
% Set the width of the lines used in plots.
function LineWidth_Callback(hObject, eventdata, handles)
   % hObject    handle to LineWidth (see GCBO)
   % eventdata  reserved - to be defined in a future version of MATLAB
   % handles    structure with handles and user data (see GUIDATA)
   handles.LnWdth=str2num(get(handles.LineWidth,'String'));
   guidata(handles.AsymBodePlot, handles);  %save changes to handles.
   BodePlotter(handles);                    %Plot the Transfer function.
   handles=guidata(handles.AsymBodePlot);   %Reload handles after function call.
end
% ------------------End of function BodePlotLegend --------


% --------------------------------------------------------------------
% Determines the line color of the ith plot.
function linecolor=GetLineColor(i,handles);
   numColors=size(handles.colors,1);
   %Cycle through colors by using mod operator.
   linecolor=handles.colors(mod(i-1,numColors)+1,:);
end
% ------------------End of function GetLineColor --------


% --------------------------------------------------------------------
% Determines the line style of the ith plot.
function linestyle=GetLineStyle(i,handles);
   numColors=size(handles.colors,1);
   numLnStl=size(handles.linestyle,2);
   %Cycle through line styles, incrementing after all colors are used.
   linestyle=handles.linestyle{mod(ceil(i/numColors)-1,numLnStl)+1};
end
% ------------------End of function GetLineStyle --------


% --------------------------------------------------------------------
% --- Executes on button press in GrayCheckBox.
% This function sets the sequence of colors used in plotting to gray scales.
function GrayCheckBox_Callback(hObject, eventdata, handles)
   if get(handles.GrayCheckBox,'Value')==1,  %If button is not set,
      handles.colors=handles.Gray;             %and set colors to gray scale
      handles.zrefColor=handles.GrayZero;
   else
      handles.colors=handles.Color;            %and set colors to RGB
      handles.zrefColor=handles.ColorZero;
   end
   guidata(handles.AsymBodePlot, handles);   %save changes to handles.
   BodePlotter(handles);                     %Plot the Transfer function.
   handles=guidata(handles.AsymBodePlot);    %Reload handles after function call.
end
% ------------------End of function BodePlotLegend --------


% --- Executes on button press in GridCheckBox.
function GridCheckBox_Callback(hObject, eventdata, handles)
   BodePlotter(handles);                     %Plot the Transfer function.
end

% --- Executes on button press in RadianCheckBox.
function RadianCheckBox_Callback(hObject, eventdata, handles)
   BodePlotter(handles);                     %Plot the Transfer function.
end

% --- Executes on button press in WebButton.
function WebButton_Callback(hObject, eventdata, handles)
   web('http://www.swarthmore.edu/NatSci/echeeve1/Ref/Bode/Bode.html','-browser')
end

% --- Executes on button press in ShowAsymptoticCheckBox.
function ShowAsymptoticCheckBox_Callback(hObject, eventdata, handles)
   BodePlotter(handles);                     %Plot the Transfer function.
end