targetCI {clinDR}

Compute the dose with confidence interval exceeding a target change from placebo for each simulated example in an emaxsim object.

Description

Selects the lowest dose from a user-specified grid of doses with confidence interval exceeding a targetted change from placebo for each simulated data set in an emaxsim object.

Usage

targetCI (object,
	target,
	dgrid,
	clev=0.90,
	high= TRUE)

Arguments

object

An emaxsim object

target

Target improvement from placebo

dgrid

The lowest dose is found by a search over a user-specified grid of doses. If dgrid is a single value, it is interpreted as the number of equally-spaced doses to select from zero to the highest dose in the simulated design.

clev

One-sided confidence interval level.

high

When TRUE, lower bounds are computed and must be higher than the target. When FALSE, upper bounds must be less than the target.

Value

Returns a vector with the lowest dose meeting the criteria. If a simulated example does not have a qualifying dose, Inf is returned.

Note

If the grid is very large (>200), execution will slow as a large number of estimates and SEs are computed.

Author(s)

Neal Thomas

See Also

emaxsim, predict.emaxsim, targetD

Examples

	## Not run: 

		# emaxsim changes the random number seed
		nsim<-100
		doselev<-c(0,5,25,50,100)
		n<-c(78,81,81,81,77)

		### population parameters for simulation
		e0<-2.465375 
		ed50<-67.481113 
		
		dtarget<-100
		diftarget<-9.032497
		emax<-solveEmax(diftarget,dtarget,log(ed50),1,e0)

		sdy<-7.967897
		pop<-c(log(ed50),emax,e0)    
		meanlev<-emaxfun(doselev,pop)  

		###FixedMean is specialized constructor function for emaxsim
		gen.parm<-FixedMean(n,doselev,meanlev,sdy)  

		D1 <- emaxsim(nsim,gen.parm,modType=3)

		target<-6
		tD<- ( (target*ed50)/(emax-target) )
		selectedDose<-targetCI(D1,target,dgrid=c(1:100)+0.5,clev=0.80,high=TRUE)
	
## End(Not run)