This internal function is called by plot_network
It plots one circle for each trait in the data object.
plot_trait_circ(trait_circ, label_gap, plot_dim, main_lwd)
None
A list with one element for each cirlce giving the coordinates of the points to plot for each circle.
The amount of space to leave between the circles and their labels
the dimensions of the plot
The line thickness for the circles