gsearly (version 1.0.0)

roundInterims: Round a gsearly design interim sample size to integer values

Description

Rounds the interim sample size to integer values.

Usage

roundInterims(mod, direct="u", full=FALSE)

Value

Returns a matrix (or matrices, if full=TRUE) of the total sample sizes (and control and treatment groups, if full=TRUE) for each outcome at interims analyses.

Arguments

mod

A fitted gsearly object from function gsearlyModel or gsearlyUser.

direct

Rounds interim sample sizes to nearest integer, upwards "u" (using ceiling) or downwards "d" (using floor).

full

Either FALSE, which provides total numbers only or TRUE which provides full details of numbers by groups.

See Also

gsearlyModel, gsearlyUser

Examples

 # For 90 percent power (pow), a call to gsearlyModel provides a feasible design
 fp <- c(0.0000,0.0010,0.0250)
 tn <- c(0.2400,0.7200,0.9750)
 rctdesign <- gsearlyModel(rmodel="fix", trecruit=36, s=3, tfu=c(3,6,12),
                  tinterims=c(16,31), pow=0.8,
                  cmodel="exponential", sd=20, rho=0.75, theta=10, fp=fp, tn=tn)
 rctdesign

 # Expected numbers of participants at interim analyses
 rctdesign$rdata$interims

 # Round design up to integer values
 round_rctdesign <- roundInterims(rctdesign, direct="u")
 round_rctdesign

 # Power for rounded design
 n <- rctdesign$rdata$n["total"]
 ninterims <- round_rctdesign
 cmodel <- rctdesign$idata$cmodel$corrmat
 userdesign <- gsearlyUser(trecruit=36, s=3, tfu=c(3,6,12), tinterims=c(16,31),
        ninterims=ninterims, n=n, cmodel=cmodel,
        sd=20, theta=10, fp=fp, tn=tn)
 userdesign
 userdesign$rdata$interims