function vherrorbar_dots(x,y,sigx,sigy)

N = length(x);
linesize = 2;
marksize = 1;
barratio = .5;
linetype = 'k';
for i = 1:N
    %plot(x(i),y(i),'o','markersize',marksize); % plot data
    
    % horizontal errorbar
%     plot([x(i)-sigx(i) x(i)+sigx(i)],...
%          [y(i) y(i)],linetype,'linewidth',linesize); 
%     plot([x(i)-sigx(i) x(i)-sigx(i)],...
%          [y(i)+barratio*sigy(i) y(i)-barratio*sigy(i)],linetype);
%     plot([x(i)+sigx(i) x(i)+sigx(i)],...
%          [y(i)+barratio*sigy(i) y(i)-barratio*sigy(i)],linetype); 
    
    % vertical errorbar
    plot([x(i) x(i)],...
         [y(i)-sigy(i) y(i)+sigy(i)],linetype,'linewidth',linesize);
    plot([x(i)-barratio*sigx(i) x(i)+barratio*sigx(i)],...
         [y(i)-sigy(i) y(i)-sigy(i)],linetype);
     plot([x(i)-barratio*sigx(i) x(i)+barratio*sigx(i)],...
         [y(i)+sigy(i) y(i)+sigy(i)],linetype);
end