Matlab: Annotation or text on graph and Find index

Hor_Cross_power = (XP{Loop(2)}((find(YP{Loop(2)}>0.05,1)))+XP{Loop(2)}((find(YP{Loop(2)}<0.05,1,'last'))))/2;

Hor_Cross_prob = (YP{Loop(2)}((find(YP{Loop(2)}>0.05,1)))+YP{Loop(2)}((find(YP{Loop(2)}<0.05,1,'last'))))/2;

text(Hor_Cross_power, Hor_Cross_prob, strcat(num2str(Hor_Cross_power,4),'dB','\rightarrow\bullet'),'HorizontalAlignment', 'right');

source: http://www.mathworks.co.uk/help/techdoc/creating_plots/f0-4741.html