function linelabel(state,ind)
%linelabel Identify a line by clicking on it.
%
% Application: Sometimes a legend just isn't good enough.
% With linelabel, clicking on a line labels it.
%
% LINELABEL turns on line labels for the lines in the current axis.
% LINELABEL(handles) turns on line labels for the lines
% specified in handles. handles is a vector of handles
% to line objects. Lines are labeled by index (the first
% line in handles is 1, the next is 2, ...)
% LINELABEL(handles,[id_vector]) specifies numerical IDs for the lines.
% id_vector must be the same length as handles
% LINELABEL(handles,{id_cell}) specifies textual IDs for the lines
% id_cell must be the same length as handles
% LINELABEL(handles,'legend') Uses the labels specified in the legend
% LINELABEL OFF turns line labeling off for the current figure
%
% Example:
% %NOTE: Interact with your plot after each call to linelabel
% s = sin(2*pi*linspace(0,1)')*(1:1:5);
% lh = plot(s);
% linelabel(lh) %Number with index.
% %Click on lines to label values.
% %Click and drag to move label
% %Right click to delete.
% linelabel off
% %Existing line labels are locked in place; can't add more
% linelabel(lh,11:15) %Provide your own numbers
% linelabel(lh,{'scott','writes','useful','MATLAB','utilities'})
% %Provide your own custom labels
% legend({'Ch1','Ch2','Ch3','Ch4','Ch5'})
% linelabel(lh,'legend') %Automatically use the labels from the legend.
%
% See also DATALABEL
%
% This function is provided as an example only. It has not been
% tested, and therefore, it is not officially supported by The
% MathWorks, Inc.
% Written by Scott Hirsch
% shirsch@mathworks.com
% Copyright 2002 - 2003 The MathWorks, Inc
%Option: if no input arguments, add indexed labels to the
% lines in the current axis.
if nargin==0
state = flipud(findobj(gca,'Type','line'));
%Find lines. Flip, since findobj returns in reverse order.
end;
if ~isstr(state) % Set the WindowButtonDownFcn (turn on linelabel)
%User call: specify handles to lines
handles = state;
if ~all(ishandle(handles))
error('Input argument must be a vector of line handles');
end;
set(gcf,'WindowButtonDownFcn','linelabel down')
set(gcf,'DoubleBuffer','on'); %eliminate flicker
%Store identity to each line as appdata
%There are four possibilities here:
%1. User doesn't specify anything (1 nargin). Use 1:length(handles)
%2. User specifies a vector. Use these. arg2 = vector
%3. User specifies a cell array of strings. arg2 = cell aray
%3. User says to use the labels in the legend. arg2 = 'legend'
%Regardless, end up with a cell array of strings. Assign one
% value to each handle, in order
if nargin<2 %1. User doesn't specify anything
ind = mat2cell(num2str((1:length(handles))'),ones(length(handles),1));
elseif strcmp(ind,'legend')
%Find the legend.
%First, look for all legends on this figure
current_axis = get(handles(1),'Parent');
current_figure = get(current_axis,'Parent');
legh = findobj(current_figure,'Tag','legend');
if isempty(legh)
error('Sorry, but you must have a legend to use this syntax.')
end;
%if we only found one legend, this is easy
if length(legh)==1
ud = get(legh,'UserData'); %Returns a struct
ind = ud.lstrings;
else
ud = get(legh,'UserData'); %Returns a cell array of structs
%Search through these to find the one belonging to our figure
found=0;
ii=0;
while ~found
ii=ii+1;
if ud{ii}.PlotHandle == current_axis
found=1;
ind = ud{ii}.lstrings;
end;
end;
end;
%Ensure that the legend had one entry per handle
if length(ind) ~= length(handles)
error('Legend must have same number of entries as the input handle vector.');
end;
elseif ~iscell(ind) %2. User specifies a vector.
%Check to be sure that index vector is same length as handles
if length(ind) ~= length(handles)
error('Index vector must be of same length as handle vector');
end;
ind = mat2cell(num2str(ind(:)),ones(length(handles),1));
else %3. User specifies a cell array of strings
if length(ind) ~= length(handles)
error('Index cell array must be of same length as handle vector');
end;
end;
for ii=1:length(handles)
setappdata(handles(ii),'Index',ind{ii});
end;
elseif strcmp(state,'down') % Execute the WindowButtonDownFcn. Add label
htype = get(gco,'Type');
tag = get(gco,'Tag');
if strcmp(htype,'line') %Line - Add text object
%User-selected point
cp = get(gca,'CurrentPoint');
x = cp(1,1); %first xy values
y = cp(1,2); %first xy values
%Which line is this?
lineno = getappdata(gco,'Index');
th = text(x,y,lineno,'HorizontalAlignment','center');
%Set background color of label. MATLAB 6.5 or higher.
v=ver('MATLAB');
v=str2num(v.Version);
if v>=6.5
set(th,'BackgroundColor','y');
end;
mh = uicontextmenu('Tag','DeleteObject', ...
'Callback','delete(gco);');
set(th,'UIContextMenu',mh);
elseif strcmp(htype,'text') %Clicked on label - switch to moving
set(gco,'EraseMode','xor')
set(gcf,'WindowButtonMotionFcn','linelabel move', ...
'WindowButtonUpFcn','linelabel up');
end
elseif strcmp(state,'move') % Execute the WindowButtonMotionFcn. move label
htype = get(gco,'Type');
tag = get(gco,'Tag');
if ~isempty(gco)
th = gco;
cp = get(gca,'CurrentPoint');
pt = cp(1,[1 2]);
x = cp(1,1); %first xy values
y = cp(1,2); %first xy values
set(th,'Position', [x y 0])
drawnow
end;
elseif strcmp(state,'up') % Execute the WindowButtonUpFcn
htype = get(gco,'Type');
tag = get(gco,'Tag');
if strcmp(htype,'text')
set(gco,'EraseMode','Normal')
set(gcf,'WindowButtonMotionFcn','')
end;
elseif strcmp(state,'off') % Unset the WindowButton...Fcns
set(gcf,'WindowButtonDownFcn','','WindowButtonUpFcn','')
end
