corr_ci: Confidence interval for correlation coefficient
Description
Computes the half-width confidence interval for correlation coefficient using
the nonparametric method proposed by Olivoto et al. (2018).
Usage
corr_ci(.data = NA, ..., r = NULL, n = NULL, by = NULL, verbose = TRUE)
Arguments
.data
A dataset containing variables only or a symmetric correlation
matrix.
...
Variables to compute the confidence interval. If not informed, all
the numeric variables from .data are used.
r
If data is not available, provide the value for correlation
coefficient.
n
The sample size if data is a correlation matrix or if r is
informed.
by
One variable (factor) to split the data into subsets. The function
is then applied to each subset and returns a list where each element
contains the results for one level of the variable in by. To split
the data by more than one factor variable, use the function
split_factors to pass subsetted data to .data.
verbose
If verbose = TRUE then some results are shown in the
console.
Value
A tibble containing the values of the correlation, confidence
interval, upper and lower limits for all combination of variables.
Details
The half-width confidence interval is computed according to the following
equation: $$CI_w = 0.45304^r \times 2.25152 \times n^{-0.50089}$$
where \(n\) is the sample size and r is the correlation coefficient.
References
Olivoto, T., A.D.C. Lucio, V.Q. Souza, M. Nardino, M.I. Diel,
B.G. Sari, D.. K. Krysczun, D. Meira, and C. Meier. 2018. Confidence
interval width for Pearson's correlation coefficient: a
Gaussian-independent estimator based on sample size and strength of
association. Agron. J. 110:1-8.
10.2134/agronj2016.04.0196