Data Centering methods
Data Centering is most important factor in a model. GGEbiplot offer 4 data centering options. Under the main menu of Models, click Centered By, and select among the following options:
- No Centering: the biplot will contain mixed information of P = M + E + G + GE.
- Grand-mean centered: the biplot will contain mixed information of P - M = E + G + GE.
- Tester centered: the biplot will contain a mixed information of P - M - E = G + GE, resulting in GGE biplots. Depending on data scaling methods, there can be different types of GGE biplots.
- Double-centered: the biplot will contain information only on P - M - E - G = GE.
Note: Although entry-centered models are not listed explicitly, they can be easily achieved by transposing the two-way data before choosing a centering method.