Internal calculation: single correlation coefficient precision (Fisher z / Machin)

Sample size for estimating a Pearson correlation coefficient with pre-specified confidence interval width w = 2*d (Machin et al. 2018, Ch.19, Equations 19.5-19.8). Matches prec_cor in the presize package for identical parameters.

Usage

calculate_single_correlation(
  r,
  epsilon = NULL,
  precision = NULL,
  alpha = 0.05,
  power = NULL
)

Arguments

r

Anticipated correlation coefficient

epsilon

Relative precision (margin d = epsilon * r)

precision

Absolute margin of error d (half-width of CI)

alpha

Type I error (two-sided CI, default 0.05)

power

Ignored (estimation design)

Value

List consumed by as_sample_size_result()