cursor.m

基于ＭＡＴＬＡＢ的辅助设计 简述了矩阵分析的重要性

% 
% CURSOR    is used to read the position (x, y coordinates) on the 
%    current plot using the cursor facility  provided  in Matlab. 
%    Also, for frequency responses, the frequency corresponding
%    to the smallest error can be found. For root locus, the corres-
%    ponding gain K can also be found. Error messages are usually 
%    given when the selected point is far from the locus on the plot. 
%    

%    Author:  Ole Barup Sorensen, Rapid Data Ltd 

%    Copyright (c) 1989-94 by Rapid Data Ltd
%    Revision 10:34  07/02/94

[x_pos,y_pos,key] = getpt(gcf,choice,ip,an_type);

Ax_x = get(gca,'Xlim');
Ax_y = get(gca,'Ylim');
Ax_rx = Ax_x(2)-Ax_x(1);
Ax_ry = Ax_y(2)-Ax_y(1);

xmin =2;
scale = 100;

if an_type == 1,
  [xmin,ii] = min(abs(w_range-x_pos*ones(size(w_range))));
  if (choice == 2)|(key == 1),
    v = abs(mmm0(ii,:)-y_pos)/Ax_ry;
  elseif (choice == 3)|(key == 2),
    v = abs(ddd(ii,:)-y_pos)/Ax_ry;
  else
    v = abs(mmm0(ii,:)-y_pos)/Ax_ry;
  end
   [xmin,i] = min(v); xmin=xmin*100;
  if xmin < 1.5,
     ic = 1;  wm = w_range(ii); mm = mmm0(ii,i); 
     pm = ddd(ii,i);
  end
elseif ((an_type == 2 & ip == 1 )| an_type == 3),
  [xmin,ii] = min(abs((mmm-x_pos*ones(size(mmm)))/Ax_rx)+ ...
  abs((ddd-y_pos*ones(size(ddd)))/Ax_ry));
  [xmin,ij] = min(xmin); xmin = scale*xmin;
elseif (an_type == 2 & ip ~= 1),
  db=1;
  szmmm=size(mmm);
  vv = abs((mmm-x_pos*ones(size(md1)))/Ax_rx)+ ...
  abs((ddd-y_pos*ones(size(pd1)))/Ax_ry);
  [xmin,ii] = min([vv; abs((md1-x_pos*ones(size(md1)))/Ax_rx)+ ...
  abs((pd1-y_pos*ones(size(pd1)))/Ax_ry)]);
  [xmin,ij] = min(xmin); xmin = scale*xmin;
  if ii(ij) > szmmm(1), ii(ij)=ii(ij)-szmmm(1); db=2;end;
elseif an_type == 4,
  [xmin,ii] = min(abs((ddd-x_pos*ones(size(ddd)))/Ax_rx)+ ...
  abs((mmm-y_pos*ones(size(mmm)))/Ax_ry));
  [xmin,ij] = min(xmin); xmin = scale*xmin;
elseif an_type == 5,
  mm0 = mmm; i1 = size(mm0); 
  if id>9,
    mm0 = [mm0 ddd];
%    i2 = size(ddd);
  end
  vv = abs((real(mm0)-x_pos*ones(size(mm0)))/Ax_rx);
  vv = vv+abs((imag(mm0)-y_pos*ones(size(mm0)))/Ax_ry);
  [xmin,ii] = min(vv);
  [xmin,ij] = min(xmin); xmin = scale*xmin;
elseif (an_type == 6 | an_type == 7),
  [xmin,ii] = min(abs(t_range-x_pos*ones(size(t_range))));
  var = mmm0(ii,:); i0 = size(var);
  for i = 1:i0(2),
    v(i) = abs((var(i)-y_pos)/Ax_ry);
    [xmin, ij] = min(v); xmin = xmin*scale; 
  end
end

set(Han_b2(4:6),'String',' ');
if xmin < 1.5,
  ic = 1;
  hold on
  plot(x_pos,y_pos,'o')
  hold off
else
  ic = 0;
end  
if an_type < 6, 
  if an_type == 5
    wm = k_range(ii(ij));
  elseif an_type ~= 1,
    wm = w_range(ii(ij));
    if an_type == 2,
      pm = atan2(ddd(ii(ij),ij),mmm(ii(ij),ij))*180/pi;
      if ip == 1,
        mm = 10*log10(mmm(ii(ij),ij)^2+ddd(ii(ij),ij)^2);
      elseif ip==2,
        mm = tan(pi*x_pos*0.5/cos(pm*pi/180));
      else
        if db == 1,
          mm = 10*log10(mmm(ii(ij),ij)^2+ddd(ii(ij),ij)^2);
        else
          mm = tan(pi*x_pos*0.5/cos(pm*pi/180));
        end
        clear db szmmm 
      end
    elseif an_type == 3,
      mm = -10*log10(mmm(ii(ij),ij)^2+ddd(ii(ij),ij)^2);
      pm = 180-atan(ddd(ii(ij),ij)/mmm(ii(ij),ij))*180/pi;
    elseif an_type == 4,
      mm = mmm(ii(ij),ij); pm = ddd(ii(ij),ij);
    end
  end
  if (an_type >= 1) & (an_type <= 4),
    if (ic == 0),
      set(Han_b2(4),'String','Sorry, the selected point is NOT')
      set(Han_b2(5),'String','on the locus ')
    else
      set(Han_b2(4),'String',['The frequency w = ' num2str(wm) ' rad/sec'])
      set(Han_b2(5),'String',['The magnitude m = ' num2str(mm) ' dB'])
      set(Han_b2(6),'String',['The phase    ph = ' num2str(pm) ' degrees'])
      clear wm mm pm
    end
  elseif an_type == 5
    if (ic == 0),
      set(Han_b2(4),'String','Sorry, the selected point is NOT')
      set(Han_b2(5),'String','on the locus ')
    else
      set(Han_b2(4),'String',['The corresponding gain = ', num2str(wm) ])
      clear wm
    end
  end
elseif an_type == 6,
  if (ic == 0),
    set(Han_b2(4),'String','Sorry, the selected point is NOT')
    set(Han_b2(5),'String','on the locus ')
  else
    set(Han_b2(4),'String',[' The time is ' num2str(t_range(ii)) ' Sec' ])
    set(Han_b2(5),'String',[' The output  ' num2str(mmm0(ii,ij)) ])
    clear ii ij 
  end
elseif (an_type == 7),
  if (ic == 0),
    set(Han_b2(4),'String','Sorry, the selected point is NOT')
    set(Han_b2(5),'String','on the locus ')
  else
    set(Han_b2(4),'String',[' The time is ' num2str(t_range(ii)) ' Sec' ])
    set(Han_b2(5),'String',[' The output  ' num2str(mmm0(ii,ij)) ])
    clear ii ij 
  end
end
   
clear icursor
set(0,'Currentfigure',Fig6);