Q: How to create a "master title" at the top of a figure with several subplots?

See the function below. Because subplot doesn't know about suptitle ("SuperTitle"), you should use this after your subplots are already on screen. It is hard to get this just right for everyone on all platforms, so there are some parameters you can tweak at the beginning of the M-file. Full support for titles above subplots is on our wish list for future versions of MATLAB.

function hout=suptitle(str)
%SUPTITLE Puts a title above all subplots.
%	SUPTITLE('text') adds text to the top of the figure
%	above all subplots (a "super title"). Use this function
%	after all subplot commands.

% Drea Thomas 6/15/95 drea@mathworks.com

% Warning: If the figure or axis units are non-default, this
% will break.

% Parameters used to position the supertitle.

% Amount of the figure window devoted to subplots
plotregion = .92;

% Y position of title in normalized coordinates
titleypos  = .95;

% Fontsize for supertitle
fs = get(gcf,'defaultaxesfontsize')+4;

% Fudge factor to adjust y spacing between subplots
fudge=1;

haold = gca;
figunits = get(gcf,'units');

% Get the (approximate) difference between full height (plot + title
% + xlabel) and bounding rectangle.

	if (~strcmp(figunits,'pixels')),
		set(gcf,'units','pixels');
		pos = get(gcf,'position');
		set(gcf,'units',figunits);
	else,
		pos = get(gcf,'position');
	end
	ff = (fs-4)*1.27*5/pos(4)*fudge;

        % The 5 here reflects about 3 characters of height below
        % an axis and 2 above. 1.27 is pixels per point.

% Determine the bounding rectange for all the plots

% h = findobj('Type','axes');   

% findobj is a 4.2 thing.. if you don't have 4.2 comment out
% the next line and uncomment the following block.
	
h = findobj(gcf,'Type','axes');  % Change suggested by Stacy J. Hills

% If you don't have 4.2, use this code instead
%ch = get(gcf,'children');
%h=[];
%for i=1:length(ch),
%  if strcmp(get(ch(i),'type'),'axes'),
%    h=[h,ch(i)];
%  end
%end

	


max_y=0;
min_y=1;

oldtitle =0;
for i=1:length(h),
	if (~strcmp(get(h(i),'Tag'),'suptitle')),
		pos=get(h(i),'pos');
		if (pos(2) < min_y), min_y=pos(2)-ff/5*3;end;
		if (pos(4)+pos(2) > max_y), max_y=pos(4)+pos(2)+ff/5*2;end;
	else,
		oldtitle = h(i);
	end
end

if max_y > plotregion,
	scale = (plotregion-min_y)/(max_y-min_y);
	for i=1:length(h),
		pos = get(h(i),'position');
		pos(2) = (pos(2)-min_y)*scale+min_y;
		pos(4) = pos(4)*scale-(1-scale)*ff/5*3;
		set(h(i),'position',pos);
	end
end

np = get(gcf,'nextplot');
set(gcf,'nextplot','add');
if (oldtitle),
	delete(oldtitle);
end
ha=axes('pos',[0 1 1 1],'visible','off','Tag','suptitle');
ht=text(.5,titleypos-1,str);set(ht,'horizontalalignment','center','fontsize',fs);
set(gcf,'nextplot',np);
axes(haold);
if nargout,
	hout=ht;
end