clusters

Clusters in cda

baptiste Auguié -- 22 June, 2014

A cluster of particles is defined in 3 dimensions by a list with 3 components: positions of the dipoles; Euler angles to orient the polarizability tensor in space; and sizes of the particles (3 semi-axes for ellipsoids). Functions are provided for a few types of common clusters, as well as for their visualisation in 3D using OpenGl or povray.

Manually defining a cluster

cl1 <- list(r = rbind(c(0, 0, 0),
                      c(0, 500, 0)),
            angles = rbind(c(0, 0, 0),
                           c(0, pi/2, pi/3)),
            sizes = rbind(c(50, 20, 20),
                          c(40, 30, 30)))
rgl.ellipsoids(cl1$r, cl1$sizes, cl1$angles, col="gold")
rgl.viewpoint( theta = 0, phi = 20, fov = 70, zoom = 1)

Predefined clusters

cl2 <- cluster_dimer(d=100, 
                          dihedral=45*pi/180, alpha1=10*pi/180, alpha2=0,
                          a=35, b=12)

rgl.ellipsoids(cl2$r, cl2$sizes, cl2$angles, col="gold")

cl2 <- cluster_chain(10, pitch=100, a=50, b=30)
rgl.ellipsoids(cl2$r, cl2$sizes, cl2$angles, col="gold")

cl3 <- cluster_helix(N=20, R0=500, pitch=1000, 
                          delta=pi/7, delta0=0, right=TRUE,
                          a=100, b=50, c=20,
                          angles="helix")
hel3 <- helix(N = 20, R0 = 500, pitch = 1000, delta = pi/7, 
             delta0 = 0, right = TRUE)
  
rgl.ellipsoids(cl3$r, cl3$sizes, cl3$angles, col="gold")