letterlabels.m

JLAB is a set of Matlab functions I have written or co-written over the past fifteen years for the p

function[h]=letterlabels(arg1,arg2,arg3)
%LETTERLABELS	For automatically putting letter labels on subplots.
%
%   LETTERLABELS puts letter labels '(a)','(b)','(c)' etc., on the
%   subplots of the current figure, in the upper left-hand corner of
%   each subplot window.
%
%   LETTERLABELS(I) specifies the labelling position, clockwise from 
%   top left: 
%
%		I=1	Top left
%		I=2	Top right
%		I=3	Bottom right
%		I=4	Bottom left
%
%   LETTERLABELS(H,I), where H is a vector of handles to subplots,
%   puts labels on the subplots indicated by H. 	
%
%   LETTERLABELS(H,I,'d'), begins the labelling with letter 'd'.
%
%   LETTERLABELS will not put the letters on the right subplots if you
%   click on them before hand (because this changes the order of the
%   subplot handles).  Also if you want to label the subplots in a 
%   nonstandard order, do this by reordering H. 
%   _________________________________________________________________
%   This is part of JLAB --- type 'help jlab' for more information
%   (C) 2000, 2004 J.M. Lilly --- type 'help jlab_license' for details        


if strcmp(arg1,'--t')
    return
end

py=0.08;
ar=get(gca,'plotboxaspectratio');
xstretch=ar(1)./ar(2);
px=py/xstretch*1.8;

firstlet=real('a');
i=1;
axhand=flipud(get(gcf,'children'));


for j=1:nargin
	xx=eval(['arg' int2str(j)]);
	if ischar(xx)
		firstlet=real(xx);
	elseif length(xx)==1 && floor(xx)==xx
		i=xx;
	else
		axhand=xx;
	end
end
nax=length(axhand);
fact=1/100;

for j=1:length(axhand)
	axes(axhand(j))
	ax=axis;
	isrevx=strcmp(get(gca,'xdir'),'reverse');
	isrevy=strcmp(get(gca,'ydir'),'reverse');

	if ~isrevx
		x1=ax(1);
		x2=ax(2);
	else
		x1=ax(2);
		x2=ax(1);
	end
	if ~isrevy
		y1=ax(3);
		y2=ax(4);
	else
		y1=ax(4);
		y2=ax(3);
	end
		
	if i==1
		t=y2-(y2-y1)*fact;
		b=y2-(y2-y1)*py;
		l=x1+(x2-x1)*fact;
		r=x1+(x2-x1)*px;
	elseif i==2
		t=y2-(y2-y1)*fact;
		b=y2-(y2-y1)*py;
		l=x2-(x2-x1)*px;
		r=x2-(x2-x1)*fact;
	elseif i==3
		t=y1+(y2-y1)*py;
		b=y1+(y2-y1)*fact;
		l=x2-(x2-x1)*px;
		r=x2-(x2-x1)*fact;
	elseif i==4
		t=y1+(y2-y1)*py;
		b=y1+(y2-y1)*fact;
		l=x1+(x2-x1)*fact;
		r=x1+(x2-x1)*px;
	end
	
	h(j)=patch([l l r r],[b t t b],'w');
	set(h(j),'edgecolor',[1 1 1])

	cx=l/2+r/2;
	cy=t/2+b/2;
	text(l+(r-l)*0.2,cy,['(' char(firstlet-1+j),')']);
	axis(ax)
end

if nargout==0 
  clear h
end