Contents - Index
Functions for gene-by-chip tables (gene expression data)
Gene expression data from microarray studies are often represented as genotype by chip two-way tables. In such studies, the purpose is not to see which gene has higher or lower overall expressions. Rather, it is to see which genes respond to the treatment or material source (chips) more strongly. Therefore, the double-centered model (model 4) is appropriate for biplot analysis of such data. Actually, this is the only useful way of this type of biplot.
Some data transformation might be necessary before conducting biplot analysis.