function hh = scatter(varargin)
%SCATTER Scatter/bubble plot.
%   SCATTER(X,Y,S,C) displays colored circles at the locations specified
%   by the vectors X and Y (which must be the same size).  
%
%   S determines the area of each marker (in points^2). S can be a
%   vector the same length a X and Y or a scalar. If S is a scalar, 
%   MATLAB draws all the markers the same size. If S is empty, the
%   default size is used.
%   
%   C determines the colors of the markers. When C is a vector the
%   same length as X and Y, the values in C are linearly mapped
%   to the colors in the current colormap. When C is a 
%   length(X)-by-3 matrix, it directly specifies the colors of the  
%   markers as RGB values. C can also be a color string. See ColorSpec.
%
%   SCATTER(X,Y) draws the markers in the default size and color.
%   SCATTER(X,Y,S) draws the markers at the specified sizes (S)
%   with a single color. This type of graph is also known as
%   a bubble plot.
%   SCATTER(...,M) uses the marker M instead of 'o'.
%   SCATTER(...,'filled') fills the markers.
%
%   SCATTER(AX,...) plots into AX instead of GCA.
%
%   H = SCATTER(...) returns handles to the scatter objects created.
%
%   Backwards compatibility
%   SCATTER('v6',...) creates patch objects instead of a scattergroup
%   object for compatibility with MATLAB 6.5 and earlier.
%  
%   Use PLOT for single color, single marker size scatter plots.
%
%   Example
%     load seamount
%     scatter(x,y,5,z)
%
%   See also SCATTER3, PLOT, PLOTMATRIX.

%   Copyright 1984-2004 The MathWorks, Inc. 
%   $Revision: 1.8.4.10 $ $Date: 2004/10/22 19:44:47 $

[v6,args] = usev6plotapi(varargin{:});
if v6
  h = Lscatterv6(args{:});
else
  [cax,args,nargs] = axescheck(args{:});
  error(nargchk(1,inf,nargs));
  [pvpairs,args,nargs,msg] = parseargs(args, nargs);
  if ~isempty(msg), error(msg); end
  error(nargchk(2,4,nargs));

  cax = newplot(cax);

  switch (nargs)
   case 2
    [x,y] = deal(args{1:nargs});
    [ls,c,m] = nextstyle(cax);
    s = get(cax,'defaultlinemarkersize')^2;
   case 3
    [x,y,s] = deal(args{1:nargs});
    [ls,c,m] = nextstyle(cax);
   case 4
    [x,y,s,c] = deal(args{1:nargs});
  end

  if isempty(s), s = 36; end

  cax = newplot(cax);

  h = specgraph.scattergroup('parent',cax,'xdata',x,'ydata',y,...
                             'sizedata',s,'cdata',c,pvpairs{:});
  set(h,'refreshmode','auto');
  plotdoneevent(cax,h);
  h = double(h);
end

if nargout>0, hh = h; end

function h = Lscatterv6(varargin)
[cax,args,nargs] = axescheck(varargin{:});
error(nargchk(2,6,nargs))

cax = newplot(cax);
filled = 0;
scaled = 0;
marker = '';
c = '';

% Parse optional trailing arguments (in any order)
nin = nargs;
while nin > 0 & isstr(args{nin})
    if strcmp(args{nin},'filled'),
        filled = 1;
    else
        [l,ctmp,m,msg] = colstyle(args{nin});
        error(msg)
        if ~isempty(m), marker = m; end
        if ~isempty(ctmp), c = ctmp; end
    end
    nin = nin-1;
end
if isempty(marker), marker = 'o'; end
co = get(cax,'colororder');

switch nin
case 2  % scatter(x,y)
    x = args{1};
    y = args{2};
    if isempty(c),
        c = co(1,:);
    end
    s = get(cax,'defaultlinemarkersize')^2;
case 3 % scatter(x,y,s)
    [x,y,s] = deal(args{1:3});
    if isempty(c),
        c = co(1,:);
    end
case 4  % scatter(x,y,s,c)
    [x,y,s,c] = deal(args{1:4});
otherwise
    error(id('InvalidInput'),'Wrong number of input arguments.');
end

if length(x) ~= length(y) | ...
        length(x) ~= prod(size(x)) | length(y) ~= prod(size(y))
    error(id('InvalidData'),'X and Y must be vectors of the same length.');
end

% Map colors into colormap colors if necessary.
if isstr(c) | isequal(size(c),[1 3]); % string color or scalar rgb
    color = repmat(c,length(x),1);
elseif length(c)==prod(size(c)) & length(c)==length(x), % is C a vector?
    scaled = 1;
elseif isequal(size(c),[length(x) 3]), % vector of rgb's
    color = c;
else
    error(id('InvalidCData'),...
    'C must be a single color, a vector the same length as X, or an M-by-3 matrix.')
end

% Scalar expand the marker size if necessary
if length(s)==1, 
    s = repmat(s,length(x),1); 
elseif length(s)~=prod(size(s)) | length(s)~=length(x)
    error(id('InvalidSData'),'S must be a scalar or a vector the same length as X.')
end

% Now draw the plot, one patch per point.
h = [];
% keeping track of scatter groups for legend
if isappdata(cax,'scattergroup');
    scattergroup=getappdata(cax,'scattergroup') + 1;
else
    scattergroup = 1;
end
setappdata(cax,'scattergroup',scattergroup);

% create an invisible handle invisible axes for temporary parent
fig = ancestor(cax,'figure');
curax = get(fig,'currentaxes');
tax = axes('parent',fig,'visible','off','handlevisibility','off');
for i=1:length(x),
    h = [h;patch('parent',tax,'xdata',x(i),'ydata',y(i),...
            'linestyle','none','facecolor','none',...
            'markersize',sqrt(s(i)), ...
            'marker',marker)];
    % set scatter group for patch
    setappdata(h(end),'scattergroup',scattergroup); 
    if scaled,
        set(h(end),'cdata',c(i),'edgecolor','flat','markerfacecolor','flat');
    else
        set(h(end),'edgecolor',color(i,:),'markerfacecolor',color(i,:));
    end
    if ~filled,
        set(h(end),'markerfacecolor','none');
    end
end
set(h,'parent',cax);
delete(tax);
set(fig,'currentaxes',curax);

function [pvpairs,args,nargs,msg] = parseargs(args,nargs)
msg = '';
% separate pv-pairs from opening arguments
[args,pvpairs] = parseparams(args);
n = 1;
extrapv = {};
% check for 'filled' or LINESPEC or ColorSpec
while length(pvpairs) >= 1 && n < 4 && isstr(pvpairs{1})
  arg = lower(pvpairs{1});
  if arg(1) == 'f'
    pvpairs(1) = [];
    extrapv = {'MarkerFaceColor','flat','MarkerEdgeColor','none', ...
               extrapv{:}};
  else
    [l,c,m,tmsg]=colstyle(pvpairs{1});
    if isempty(tmsg)
      pvpairs(1) = [];
      if ~isempty(l) 
        extrapv = {'LineStyle',l,extrapv{:}};
      end
      if ~isempty(c)
        extrapv = {'CData',ColorSpecToRGB(c),extrapv{:}};
      end
      if ~isempty(m)
        extrapv = {'Marker',m,extrapv{:}};
      end
    end
  end
  n = n+1;
end
pvpairs = [extrapv pvpairs];
if isempty(args)
  msg.message = 'Must supply X and Y data as first arguments.';
  msg.identifier = id('NoDataInputs');
else
  msg = checkpvpairs(pvpairs);
end
nargs = length(args);

function [color,msg] = ColorSpecToRGB(s)
color=[];
msg = [];
switch s
 case 'y'
  color = [1 1 0];
 case 'm'
  color = [1 0 1];
 case 'c'
  color = [0 1 1];
 case 'r'
  color = [1 0 0];
 case 'g'
  color = [0 1 0];
 case 'b'
  color = [0 0 1];
 case 'w'
  color = [1 1 1];
 case 'k'
  color = [0 0 0];
 otherwise
  msg.message = 'Unrecognized color string.';
  msg.identifier = id('UnrecognizedColorString');
end

function str = id(str)
str = ['MATLAB:scatter:' str];