Before you start an analysis, you can use the Grouping & Quantification page in the study to define sample groups of files that the Feature Mapper node should group, or align, together. You usually group files having equal properties, such as replicate files.
For the example shown in this chapter, these samples are grouped as shown in the following figure.
For these data, the application first separately aligns each of the sample groups based on the E. coli (ng) study factor. It first independently aligns the three files found for the sample group E. Coli (ng): 3. Then it independently aligns the three files for E. coli (ng): 7.5, E. coli (ng): 10, and E. coli (ng): 15. Subsequently, it aligns the selected reference files for each sample group to each other. The selection of the reference file depends on the alignment node. The Feature Mapper node takes the file with the most features.