polarstr(theta,rho,line_style)

function polarstr(theta,rho,line_style)
%
% polarstr(theta,rho,line_style)
% ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
% This is a modified version of MATLAB's
% standard plotting routine.  This version
% has been tailored for this specific problem
% and is not for general polar plotting.
%
% theta      - the angle vector (radians)
% rho        - the radius vector
% line_style - one of MATLAB's linestyles
%
% User m functions called:  none
%----------------------------------------------

% get hold state
hold_state = ishold;

%...Only do grids if hold is off
if ~hold_state
  %...Make a radial grid
  hold on;
  hhh=plot([0 max(theta(:))], ...
           [0 max(abs(rho(:)))],'y:');
  v=[get(gca,'xlim') get(gca,'ylim')];
  ticks=length(get(gca,'ytick'));
  delete(hhh);
  %...Check radial limits and ticks
  rmin=0; rmax=v(4); rticks=ticks-1;
  if rticks > 5	
    %...Can we reduce the number
    if rem(rticks,2) == 0
      rticks=rticks/2;
    elseif rem(rticks,3) == 0
      rticks=rticks/3;
    end
  end
  %...Define a circle
  th=0:pi/50:2*pi;
  xunit=cos(th); yunit=sin(th);
  %...Force points to lie on x/y axes 
  inds=[1:(length(th)-1)/4:length(th)];
  xunits(inds(2:2:4))=zeros(2,1);
  yunits(inds(1:2:5))=zeros(3,1);
  rinc=(rmax-rmin)/rticks;
  for i=(rmin+rinc):rinc:rmax
    plot(xunit*i,yunit*i,'y:','linewidth',0.5);
    if (i ~= rmin+rinc) & (i ~= rmax)
      text(0,i+rinc/20,['  ' num2str(i)], ...
           'verticalalignment','bottom' );
    end
  end
%...Plot spokes
  th=(1:6)*2*pi/12;
  cst=cos(th); snt=sin(th);
  cs=[-cst; cst]; sn=[-snt; snt];
  plot(rmax*cs,rmax*sn,'y:','linewidth',0.5);
%...Annotate spokes in degrees
  rt=1.1*rmax;
  for i = 1:max(size(th))
    text(rt*cst(i),rt*snt(i), ...
         int2str(i*30), ...
         'horizontalalignment','center' );
    if i == max(size(th))
      loc=int2str(0);
    else
      loc=int2str(180+i*30);
    end
    text(-rt*cst(i),-rt*snt(i),loc, ...
         'horizontalalignment','center' );
  end
  %...Set axis limits
  axis(rmax*[-1 1 -1.1 1.1]);
end

%...Transform data to Cartesian coordinates.
xx=rho.*cos(theta); yy=rho.*sin(theta);
plot(xx,yy,line_style);