Annotation pinned to axes

This function extends the standard annotation function by making them pinned to the axes.

I needed to be able to create annotations to plots that would be pinned to the axes like the text function. I couldn't find any script to do this so I made my own. I though other people may find it useful.

The only difference in use with the annotation function is that you can provide the axes handle. For example:
figure
ah1=subplot(2,1,1);
annotation_pinned('textarrow',[0.6,0.7],[0.3,0.5],'String','simple text','Interpreter','Latex')
ah2=subplot(2,1,2);
annotation_pinned('arrow',[0.1,0.2],[0.5,0.1],'axes',ah1);
annotation_pinned('textarrow',[0.3,0.5],[0.3,0.5],'axes',ah2,'String','test $x^2$','Interpreter','Latex')