Figure 2
From: Relationship of SARS-CoV to other pathogenic RNA viruses explored by tetranucleotide usage profiling
Relationship between the number of eigen-vectors retained and the percentage of the variance they represent in the entire usage patterns for 31 viruses. As each consecutive factor is defined to identify a usage pattern that is not captured by the preceding eigen-vectors, each consecutive factors are therefore independent of each other. In addition, the order for the consecutive eigen-vectors is extracted with diminishing importance.