Use this if you are using igraph from R
Sample finite-dimensional vectors to use as latent position vectors in random dot product graphs
sample_sphere_surface(dim, n = 1, radius = 1, positive = TRUE)
dim |
Integer scalar, the dimension of the random vectors. |
n |
Integer scalar, the sample size. |
radius |
Numeric scalar, the radius of the sphere to sample. |
positive |
Logical scalar, whether to sample from the positive orthant of the sphere. |
sample_sphere_surface
generates uniform samples from S^{dim-1}
(the (dim-1)
-sphere) with radius radius
, i.e. the Euclidean
norm of the samples equal radius
.
A dim
(length of the alpha
vector for
sample_dirichlet
) times n
matrix, whose columns are the sample
vectors.
Other latent position vector samplers: sample_dirichlet
,
sample_sphere_volume
lpvs.sph <- sample_sphere_surface(dim=10, n=20, radius=1) RDP.graph.3 <- sample_dot_product(lpvs.sph) vec.norm <- apply(lpvs.sph, 2, function(x) { sum(x^2) }) vec.norm