Create a monopole antenna and calculate the directivity at 1 GHz.
m = monopole;
M = pattern(m,1e9,0,0:1:360);
Plot the polar pattern and show three peaks of the antenna. When creating a polarpattern plot, if you specify the Peaks property, the peaks table is displayed by default.
P = polarpattern(M,Peaks=3);
Hide the table. When the peaks table is hidden, the peak markers display the peak values.