Contents - Index

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.