drawgroup2: drawgroup2
In jtm508/bayestraj:

Draw second series' groups from posterior distribution

1	drawgroup2(X, y, N, id, g1, pi1, pi1_2, beta, sigma, K)

`X:`	Matrix, design matrix
`y:`	Vector, outcomes
`N:`	Integer, number of tandems
`id:`	Vector, tandem for each row of X and Y
`g1:`	Vector, group membership for series 1
`pi1:`	Vector, group probabilities for series 1
`pi1_2:`	Vector, transition probabilities for series 2
`beta:`	Matrix, likelihood coefficients for series 1
`sigma:`	Float or vector, likelihood variance
`K:`	Number of groups in series 1