# dielectric function
wvl <- seq(400, 800, length=200)
gold <- epsAu(wvl)

# cluster, and single particle for reference
cl <- cluster_dimer(dihedral = 0,  a=35, b=20)
clr <- cluster_single(a=35, b=20)

nn <- 7
Incidence <- rep(seq(0,pi/2,length=nn), 3)
Axes <- rep(c("x", "y", "z"), each=nn)

d <- spectrum_dispersion(cl, gold, medium=1.33, 
                                     polarisation = "linear",
                                     Incidence=Incidence, Axes=Axes,
                                     method = 'solve')

id <- c(1, 1+nn, 1+2*nn)
dr <- spectrum_dispersion(clr, gold, medium=1.33, 
                                    polarisation = "linear",
                                    Incidence=Incidence[id], Axes=Axes[id],
                                    method = 'solve')