function varargout=boxtex...
    (posi,handel,index,fontsize,kees,hitmul,widmul,posxmul,posymul)
% [bcor,tcor]=BOXTEX(posi,handel)
% BOXTEX(posi,handel,index,fontsize)
% [bhan,than]=BOXTEX...
%   (posi,handel,index,fontsize,kees,hitmul,widmul,posxmul,posymul)
%
% Puts an intelligent text box on a plot
%
% INPUT:
%
% posi         'll','lr','ul','ur','um','lm', OR two coordinates
% handel       Axis handle on which you'll put the legend
% index        Plotnumber, as letter of the alphabet, OR text string
% fontsize     Font size [default: 20]
% kees         1 Upper case [default]
%              0 or Anything else: Lower case
%              2 Actual numbers
% hitmul       Multiplies height by this factor [default: 1]
% widmul       Multiplies width by this factor [default: 1]
% posxmul      Multiplies x-margin [default: dataaspectratio]
% posymul      Multiplies y-margin [default: dataaspectratio]
%
% OUTPUT:
%
% bcor         Coordinates of box
% tcor         Coordinates of text
% bhan         Handle to box
% than         Handle to text
% 
% EXAMPLE I:
%
% plot(1:10)
% boxtex('lr',gca,3,10)
%
% EXAMPLE II:
%
% load clown; image(X)
% b=boxtex('ul',gca,'This is a clown',12)
% set(b,'FaceColor','y','EdgeColor','b')
% 
% See also: LABEL, FILLBOX
%
% Last modified by fjsimons-at-alum.mit.edu, 09/19/2007

defval('posi','ll')
defval('index',1)
defval('fontsize',20)
defval('handel',gca)
defval('kees',1)
defval('hitmul',1)
defval('widmul',1)

axes(handel)
xl=get(handel,'xlim');
yl=get(handel,'ylim');
rxl=range(xl);
ryl=range(yl);

%-----------------------------------------------
% Specify height and width of box and margins
% in proportion of the FONTSIZE (default 20)
if isstr(index)
  watis=index;
else
  watis= 'M';
end
a=text(0,0,watis,'fonts',fontsize); ext=get(a,'Extent');
delete(a)
[wid,hit]=deal(ext(3),ext(4));
hit=hit*hitmul;
wid=wid*widmul;
xmrg=0.025; % Margin as ratio of xlim
ymrg=0.025; % Margin as ratio of ylim
% Actually, this needs to be updated depending on the data aspect ratio
da=get(handel,'dataaspectratio'); % This is the 09/19/07 update!!
if da(1)>da(2)
  defval('posxmul',da(2)/da(1)*2)
  defval('posymul',1)
elseif da(1)>da(2)
  defval('posxmul',1)
  defval('posymul',da(1)/da(2)*2)
else
  defval('posxmul',1)
  defval('posymul',1)
end
% BUT NOT ALWAYS... FORCE TO 1 SOMETIMES

% Make these adjustments
xmrg=xmrg*posxmul;
ymrg=ymrg*posymul;
%-----------------------------------------------

% Define mirroring operators
Mx=[ 1,-1];
My=[-1, 1];

% Define one box in upper right relative to midpoint
mid=boxmid([xl yl]);
% Define Left and Top corner, shifted by MID
X1=[xl(2)-rxl*xmrg-wid yl(2)-ryl*ymrg        ]-mid;
% Define Right and Bottom corner, shifted by MID
X2=[xl(2)-rxl*xmrg         yl(2)-ryl*ymrg-hit]-mid;

if isstr(posi)
  switch posi
   case 'ur'
    [B1,B2]=deal(X1,X2);
   case 'lr'
    [B1,B2]=deal(Mx.*X1,Mx.*X2);
   case 'ul'
    [B1,B2]=deal(My.*X1,My.*X2);
   case 'll'
    [B1,B2]=deal(My.*Mx.*X1,My.*Mx.*X2);
   case 'um'
    [B1,B2]=deal([-wid/2 X1(2)],[wid/2  X2(2)]);
   case 'lm'
    [B1,B2]=deal([-wid/2 -X1(2)],[wid/2  -X2(2)]);
  end      
else
  B1=[posi(1)-wid/2 posi(2)+hit/2];
  B2=[posi(1)+wid/2 posi(2)-hit/2];
  mid=0;
end

% Shift the MID back in
B1=B1+mid;
B2=B2+mid;
bcor=[B1(1) B2(1) B1(2) B2(2)];
tcor=boxmid(bcor);

if nargin>2
  hold on
  bhan=fillbox(bcor,[1 1 1],1);  
  if isstr(index)
    than=text(tcor(1),tcor(2),1.1,index,'FontSize',fontsize,...
	'HorizontalAlignment','Center');
  else
    if kees>=2
      than=text(tcor(1),tcor(2),1.1,num2str(index),...
		'FontSize',fontsize,'HorizontalAlignment','Center'); 
    else
      than=text(tcor(1),tcor(2),1.1,letter(index,kees),...
		'FontSize',fontsize,'HorizontalAlignment','Center'); 
    end
  end
  if nargout
    varargout{1}=bhan;
    varargout{2}=than;
  end
else
    if nargout
    varargout{1}=bcor;
    varargout{2}=tcor;
  end
end