Threshold evaluation. The number of cyclic expressed genes using different cutoffs for the angular distance method are shown. The threshold value resulting in the maximum number of oscillating genes for both microarray data sets was chosen for the final classification. The blue graph corresponds to the cyclic genes from the Stöckel et al. data set  and the green graph shows the oscillating genes from the Toepel et al. data set .
Elvitigala et al. BMC Genomics 2009 10:226 doi:10.1186/1471-2164-10-226