2.3.7. New Samples and Cross-Validation
The method was applied to a group of blood samples from ten different diseases and controls. We used the entire data set of ten diseases and controls to identify gene expression biomarkers associated with each of the ten diseases using the statistical method described above (one-against-all). This is the first data set collected entirely in PAXgene tubes. Because the sample numbers are still small, it is not practical to evaluate prediction performance by partition into a traditional training/test sets. Instead, we performed a 2-fold cross-validation iterated 1000 times.
Figure 3  Estimating the value of π numerically. (a) Convergence speed using a systematic search (b) and a Monte-Carlo random search (c).

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