For a regular plot, you can use the Data Tips icon on the axtoolbar to manually select the points you want to view. To do it programatically, you would need to use the function datatip.
x = 0:20;
y = x.^2;
p = plot(x,y);
datatip(p,x(10),y(10));
or if you want to add custom information, you can use dataTipTextRow
x = 0:20;
y = x.^2;
str = "Value #" + (0:20)';
p = plot(x,y);
row = dataTipTextRow('ID',str);
p.DataTipTemplate.DataTipRows(end+1) = row;
datatip(p,x(10),y(10));
