art wrote:

The subject was antenna radiation patterns and ascertaining the
relative volume of the main lobe which is the reason for an antenna and
comparing it to the total volume of the array which one accepts to
obtain the desirable primary lobe.

Take the integral of the gain of the antenna over the angles in azimuth
and elevation that you consider to define the boundaries of the main
lobe and divide that by the integral of the gain of the antenna over
all angles . You'll need your gain as a function of the angles.

That's the number you're looking for, I suppose. I guess it's a decent
measure of sidelobe suppression... but so is the ratio of the gain of
the main lobe to the gain of the biggest sidelobe.

73,
Dan