BPSStudentT: BPSStudentT

In RZigZag: Zig-Zag Sampler

Description

Applies the Zig-Zag Sampler to a Student T distribution (IID or spherically symmetric)

Usage

BPSStudentT(dof, dim = 1L, n_iter = -1L, finalTime = -1,
  x0 = numeric(0), v0 = numeric(0), sphericallySymmetric = TRUE,
  refresh_rate = 1, unit_velocity = FALSE)

Arguments

dof	scalar indicating degrees of freedom
dim	dimension
n_iter	Number of algorithm iterations; will result in the equivalent amount of skeleton points in Gaussian case because no rejections are needed.
finalTime	If provided and nonnegative, run the sampler until a trajectory of continuous time length finalTime is obtained (ignoring the value of n_iterations)
x0	starting point (optional, if not specified taken to be the origin)
v0	starting direction (optional, if not specified taken to be a random vector)
sphericallySymmetric	boolean. If false, sample iid Student T distribution, if true (default) sample spherically summetric Student t dsitribution.
refresh_rate	lambda_refresh
unit_velocity	TRUE indicates velocities uniform on unit sphere, FALSE (default) indicates standard normal velocities

Value

Returns a list with the following objects:

Times: Vector of switching times

Positions: Matrix whose columns are locations of switches. The number of columns is identical to the length of skeletonTimes. Be aware that the skeleton points themselves are NOT samples from the target distribution.

Velocities: Matrix whose columns are velocities just after switches. The number of columns is identical to the length of skeletonTimes.

Examples

dim = 2
dof = 4
result <- BPSStudentT(dof, dim, n_iter=1000,sphericallySymmetric = TRUE)
plot(result$Positions[1,], result$Positions[2,],type='l',asp=1)

RZigZag documentation built on July 20, 2019, 9:03 a.m.