Computes approximate one-sided or two-sided prediction limits for the estimated Pearson correlation in a future study with a planned sample size of n. The prediction interval uses a correlation estimate from a prior study that had a sample size of n0.
Several confidence interval sample size functions in this package require a planning value of the estimated Pearson correlation that is expected in the planned study. A one-sided lower correlation prediction limit is useful as a correlation planning value for the sample size required to obtain a confidence interval with desired width. This strategy for specifying a correlation planning value is useful in applications where the population correlation in the prior study is assumed to be very similar to the population correlation in the planned study.
Arguments
- alpha
alpha value for 1-alpha confidence
- cor
estimated Pearson correlation from prior study
- n0
sample size used to estimate correlation in prior study
- n
planned sample size of future study
- type
set to 1 for two-sided prediction interval
set to 2 for one-sided upper prediction limit
set to 3 for one-sided lower prediction limit