That's a little more tricky and the examples don't illustrate -- but it's not terribly difficult to fix; the problem is 'VerticalAlignment' property needs to be sensitive to the sign of the data. One either has to do a double-index loop or keep the loop by bar handle and then fixup each position in the end...
y = [1 2 3 4 ; 2 3 -4 5 ; -6 -10 5 7 ; -1 -5 8 7];
hB=bar(y);
% preallocate the text handles for text objects NB bars are by column; but
% text handles are row vector so transpose to preallocate the text object handles
hTxt=gobjects(size(y.'));
% iterate over bar groups; again NB row vector of text handles returned by text
for i=1:numel(hB)
hTxt(i,:)=text(hB(i).XData+hB(i).XOffset,hB(i).YData,num2str(hB(i).YData.','%d'), ...
'VerticalAlignment','bottom','horizontalalign','center');
end
% now the magic fixup by sign for vertical alignment -- can set all at once after the fact
set(hTxt((y.'<0)),{'VerticalAlign'},{'top'})
ylim(12*[-1 1]) % make a little more room to put labels inside box
The alternative is one has to write a second loop over the number of YData values in each bar handle and use if/else construct on each value to set the alignment.
