Cluster profiles of k-means clusters.

<p>(A) Pearson correlation and (B) Euclidean distance as distance measure. Each line represents a gene and color is used to distinguish individual genes in dense clusters. Euclidean clusters appear denser with genes being grouped together based on height along the Y-axis (gene expression). The clustering based on Pearson correlation appears sparser with genes grouped together based on the shape of expression profiles over time.