krow: Up-and-Down Design Rules for use in Dose-Finding Simulator

View source: R/simulate.r

krowR Documentation

Up-and-Down Design Rules for use in Dose-Finding Simulator

Description

Rules for k-in-a-row, Biased-Coin UD, and Group UD, coded as functions compatible with the generic dose-finding simulator dfsim()

These functions work on each virtual experimental run individually.

Usage

krow(doses, responses, k, lowTarget = NULL, fastStart = FALSE, ...)

bcd(doses, responses, coin, lowTarget, fastStart = FALSE, ...)

groupUD(doses, responses, s, ll, ul, ...)

Arguments

doses, responses

(mandatory arguments) vectors of the run's current sequence of doses (in ordinal/index scale) and responses

k

the number of consecutive identical responses required for dose transitions (k-in-a-row functions only).

lowTarget

(krow and bcd) logical: is the target below 0.5 (median threshold)?

fastStart

(krow and bcd) logical: should the experiment begin with a classical-UD-like stage until the first "minority" response is observed (i.e., a 1 for below-median targets and vice versa)? Even though TRUE delivers better experimental performance and is recommended when allowed, default is FALSE because toxicity/safety studies are unlikely to allow it.

...

Technical pass-through argument, to allow for flexibility when constructing design-comparison simulation ensembles.

coin

(bcd only) the biased-coin probability. Note that unlike bcdmat(), here the function does not figure out automatically the coin probability and upper/lower target location from the provided target.

s

(groupUD only) the group/cohort size, analogous to cohort in gudmat(). We use a different name here because cohort is already used in dfsim that calls these utilities.

ll, ul

(groupUD only) how many positive responses are allowed for a move upward, and how many are required for a move downward, respectively. Analogous to ⁠lower, upper⁠ in gudmat(). For example ⁠s=3, ll=0, ul=2⁠ evaluates groups of 3 observations at a time, moves up if none are positive, down if >=2 are positive, and repeats the same dose with 1 positive.

Details

Rules for some popular or well-studied non-up-and-down

Value

the next dose allocation


upndown documentation built on April 3, 2025, 10:57 p.m.