Generate scale-free network skeleton and simulates corresponding precision matrix

A utility function generates scale-free network skeleton and simulates corresponding precision matrix. The non-zero elements of the precision matrix are generated randomly from a uniform distribution with parameters (-upper, -lower) UNION (lower, upper).

Usage

make_sf_precision_mat(
  e = 1,
  power = 1,
  p = 20,
  lower = 0.2,
  upper = 0.5,
  diag = 0.1
)

Arguments

e: Numeric constant, the number of edges to add in each time step, see sample_pa().
power: Numeric constant, the power of the preferential attachment for scale-free network, the default is 1, , see sample_pa().
p: A positive integer, the number of vertices.
lower: A positive number, lower limits of the uniform distribution.
upper: A positive number, upper limits of the uniform distribution.
diag: A small positive number to be added to diagonal elements, which guarantees the precision matrix is positive definite.

Value

A precision matrix of size p by p.

Examples

Omega = make_sf_precision_mat(e=1, p=10)