b_samp: Sample subject specific random effects
In bpnreg: Bayesian Projected Normal Regression Models for Circular Data

Sample subject specific random effects

1	b_samp(Omega, beta, R, theta, X, q, Z, ZtZ, N)

`Omega`	current covariance matrix
`beta`	current fixed effect coefficients vector
`X`	design matrix model parameters (differs per person)
`q`	dimension Z(number of random effects)
`Z`	design matrix for random effects (differs per person)
`ZtZ`	transpose(Z)*Z
`N`	sample size at second level
`Y`	current outcome vector (Y.I=cos(theta)R, Y.II=sin(theta)R)