VNM (version 1.0)

ceff1: Checking c-efficiency for estimating the ED50.

Description

Obtaining c-efficiency for estimating the ED50 for a given design under the 4-parameter logistic model. Here the ED50 is the dose producing a 50

Usage

ceff1(weight,T,dose,nit,LB,UB)

Arguments

weight

A numeric vector. Weights for a given design. The weights represent the proportional allocations of subjects to the dose levels in a given design.

T

A numeric vector. Predetermined parameter values for the 4-parameter logistic model. T=c(t1, t2, t3, t4).

dose

A vector. K dose levels for a given design.

nit

Numeric. The number of iterations to set an initial design to search c-optimal design for estimating the ED50. Default is 1 and needed to be increased (for example, nit=10 or 30 or 50) if the searched c-optimal design is not a true optimal. It can be veri

LB

Numeric. Predetermined lower bound of the dose range for the log dose.

UB

Numeric. Predetermined upper bound of the dose range for the log dose.

Value

• 1. c-optimal design for estimating the ED50; 2. A verification plot of the c-optimal design for estimating the ED50 by the General Equivalence Theorem; 3. c-efficiency for estimating the ED50 for a given design.

References

Seung Won Hyun, Weng Kee Wong, and Yarong Yang (2013), Multiple Objective Optimal Designs to Study the Interesting Features in a Dose-Response Relationship, forthcoming.

Examples

T1<-c(-1.563,-1.790,-8.442,1.700)
  dose1<-c(-4,-2.23,-1.14,1.00)
  weight1<-c(0.309,0.254,0.290)
  weight1<-c(weight1,1-sum(weight1))
  ceff1(weight=weight1,T=T1,dose=dose1,nit=10,LB=-6.91,UB=6.91)