samplesize.bin: Sample Size for 2-sample Binomial In harrelfe/Hmisc: Harrell Miscellaneous

 samplesize.bin R Documentation

Sample Size for 2-sample Binomial

Description

Computes sample size(s) for 2-sample binomial problem given vector or scalar probabilities in the two groups.

Usage

``````samplesize.bin(alpha, beta, pit, pic, rho=0.5)
``````

Arguments

 `alpha` scalar ONE-SIDED test size, or two-sided size/2 `beta` scalar or vector of powers `pit` hypothesized treatment probability of success `pic` hypothesized control probability of success `rho` proportion of the sample devoted to treated group (`0 <\code{rho} < 1`)

Value

TOTAL sample size(s)

AUTHOR

Rick Chappell
Dept. of Statistics and Human Oncology
chappell@stat.wisc.edu

Examples

``````alpha <- .05
beta <- c(.70,.80,.90,.95)

# N1 is a matrix of total sample sizes whose
# rows vary by hypothesized treatment success probability and
# columns vary by power
# See Meinert's book for formulae.

N1 <- samplesize.bin(alpha, beta, pit=.55, pic=.5)
N1 <- rbind(N1, samplesize.bin(alpha, beta, pit=.60, pic=.5))
N1 <- rbind(N1, samplesize.bin(alpha, beta, pit=.65, pic=.5))
N1 <- rbind(N1, samplesize.bin(alpha, beta, pit=.70, pic=.5))
attr(N1,"dimnames") <- NULL

#Accounting for 5% noncompliance in the treated group
inflation <- (1/.95)**2
print(round(N1*inflation+.5,0))
``````

harrelfe/Hmisc documentation built on May 19, 2024, 4:13 a.m.