tcl 1.0.1

mix_mod() added: fits a mixed model considering multiple covariates.
Power calculation and power curve functions added for statistical analysis and visualization.
Backtick issues in sample_size_planning outputs fixed for improved readability.
Function arguments and return values harmonized across the package for consistency and ease of use.

tcl 0.2.1

function “Testing item discriminations” added
invar_test() function update: RS test statistic computable, in case Group 1 and/or 2 model not identified from the data.
minor bug fixes

First CRAN release.