Fig. 3. Correlating a spectrum of phenotypes. A set of 14 phenotypes for eight genes is indicated by the presence (blue) or absence (yellow) of the phenotype. In this example, genes A and B are perfectly correlated (14 of 14 phenotypes), genes C and D are tightly correlated (12 of 14 phenotypes), and genes A-D are more correlated with each other than with E-H. This data representation allows genes and phenotypes to be clustered and calculations of pairwise correlation coefficients to be made.