Figure 2

The distribution of points on the principal plane spanned by the first ( x ) and second ( y ) principal axes using the principal component analysis (PCA) in At 58. The red circles represent the function-known genes, the blue triangles represent the corresponding negative samples and the black stars denote the recognized non-coding ORFs. The first and second principal axes account for 33.96% and 14.98% of the total inertia of the 21-dimensional space, respectively. It is clear that most of the identified non-coding ORFs distribute far from the core of open circles, and close to the core of open triangles, which implies that the recognized non-coding ORFs are very unlikely to encode proteins.