There are several non-functional-form-based interaction tests for testing interaction in unreplicated two-way layouts. However, no single test can detect all patterns of possible interaction and the tests are sensitive to a particular pattern of interaction. This package combines six non-functional-form-based interaction tests for testing additivity.

These six tests were proposed by Boik (1993), Piepho (1994), Kharrati-Kopaei and Sadooghi-Alvandi (2007), Franck et al. (2013), Malik et al. (2016) and Kharrati-Kopaei and Miller (2016). The p-values of these six tests are combined by Bonferroni, Sidak, Jacobi polynomial expansion, and the Gaussian copula methods to provide researchers with a testing approach which leverages many existing methods to detect disparate forms of non-additivity. This package is based on the following published paper: Shenavari and Kharrati-Kopaei (2018) A Method for Testing Additivity in Unreplicated Two-Way Layouts Based on Combining Multiple Interaction Tests. In addition, several sentences in help files or descriptions were copied from that paper.

• In the name of two-part functions, '.' changed to '_'. For example, the function 'Boik.test' changed to Boik_test.

• All reports of tests are tidy and justified.

• The function 'interactionplot' changed to 'interaction_plot'

• The function CPI_test changed to 'CI_test'.

• The function 'justify' were added as utiles functions to make tidy the reports.

• Some unit tests were added to the package.

Some bugs in CI_test, Boik_test, Piepho_test, 'KKSA_test', 'KKM_test' are Fixed, 'Malik_test', and Franck_test. Some typos were corrected in function documents. In addition, ITtestClass_methods, combtest_methods, and plots` were improved.

You can install this R package from this GitHub repository with:

# install.packages("remotes")
remotes::install_github("haghbinh/combinIT")