Attach the windfarmGA class so print() and plot()
dispatch. New runs from genetic_algorithm() already have this class.
print() shows run inputs, the wind table, and each generation that
set a new fitness maximum.
as_windfarmGA(x)# S3 method for windfarmGA
print(x, ...)
# S3 method for windfarmGA
plot(x, y, ...)
x with class windfarmGA.
A result matrix from genetic_algorithm().
Passed to plot_windfarmGA().
The site polygon (same as area in genetic_algorithm()).