Create a repeated measures correlation matrix.

## Arguments

- participant
A variable giving the subject name/id for each observation.

- variables
A character vector indicating the columns of variables to include in the correlation matrix.

- dataset
The data frame containing the variables.

- CI.level
The level of confidence intervals to use in the rmcorr models.

## Value

A list with class "rmcmat" containing the following components.

- matrix
the repeated measures correlation matrix

- summary
a dataframe showing rmcorr stats for each pair of variables

- models
a list of the full rmcorr model for each pair of variables

## References

Bakdash, J.Z., & Marusich, L.R. (2017).
Repeated Measures Correlation. *Frontiers in Psychology, 8*, 456.
doi:10.3389/fpsyg.2017.00456
.

Bland, J.M., & Altman, D.G. (1995). Calculating correlation
coefficients with repeated observations: Part 1 -- correlation within
subjects. *BMJ, 310*, 446, doi:10.1136/bmj.310.6977.446
.

Cohen, P., West, S. G., & Aiken, L. S. (2002). *Applied multiple
regression/correlation analysis for the behavioral sciences* (3rd edition),
Routledge. ISBN: 9780805822236.