Sample Size for One Proportion Test

sample.size.for.one.proportion.test <- function(p0  = 0.8, p1 = 0.9, alpha = 0.025, beta = 0.2)
{
    ## Purpose: Sample Size for One Proportion Test.
    ##   H0: p <= p0
    ##   H1: p >  p0
    ##   (Application: tests of sensitivity, specificity with performance goals)
    ## Arguments:
    ##   p0: performance goal (minimally acceptable proportion). Default to 80%. 
    ##   p1: expected performance (minimal proportion under the alternative hypothesis). Defaul to 90%. 
    ##   alpha: type I error. Default to 0.025 (for one-sided test).
    ##   beta: type II error (1 - power). Default to 0.2 (so power is 80%). 
    ## Return:
    ##   Sample Size
    ## Author: Feiming Chen
    ## Reference: Biswas, Bipasa. "Clinical performance evaluation of molecular diagnostic tests."
    ##            The Journal of Molecular Diagnostics 18.6 (2016): 803-812.
    ## ________________________________________________

    N = (qnorm(1 - alpha) * sqrt(p0 * (1 - p0)) + qnorm(1 - beta) * sqrt(p1 * (1 - p1)))^2 / (p1 - p0)^2
    ceiling(N)
}
if (F) {                                # Unit Test
    sample.size.for.one.proportion.test() # 108 (PASS output: 107 under exact test; 108 under normal approx.)
}