vtDecMap {visit}

Obtain decision map information

Description

Summarize the posterior distribution of \theta^{(l)}_{00}, \theta^{(l)}_{01}, \theta^{(l)}_{10}, \theta^{(l)}_{11} and get information for making dose escalation decisions

Usage

vtDecMap(thetas, etas, prev.res = 0, dec.cut = 0.6)

Arguments

thetas

Posterior samples of \theta, a class VTPOST matrix generated by vtPost

etas

Vector of length 2 representing (p_L, p_U). p_L: lower bound of DLT risk, below which the current dose is considered absolutely safe; p_U: upper bound of DLT risk above which the current dose is considered too toxic

prev.res

Response rate from the next lower dose level, say, l-1. This can be a scalar representing the mean of the response rate E(q^{(l-1)}), or a vector of posterior samples of the response rate q^{(l-1)}. For l=1, this value is set to 0.

dec.cut

Thresholds C_1,C_2,C_3. If the vector length is shorter than 3, it is repeated to have 3 elements. See visit for details.

Details

This function summarizes the posterior distribution of the \theta^{(l)}_{00}, \theta^{(l)}_{01}, \theta^{(l)}_{10}, \theta^{(l)}_{11} and sequentially get the conditional probabilities of each decision map region. See visit for details of the decision map regions.

Value

A class VTDEC list. See the return value from vtInterim for details.

Examples

etas     <- c(0.1, 0.3)
dec.cut  <- c(0.6,0.6,0.6)
obs.y    <- rbind(c(5, 2, 0, 0))
rst.post <- vtPost(obs.y,  prob.mdl = "NONPARA", nsmp = 2000)
dec.map  <- vtDecMap(rst.post, etas = etas, dec.cut = dec.cut)