7 Protocol 4 - Provenance data with shipwrecks

The following example applies protocol 4 to confirm shipwrecks samples attribution to workshops’ provenance groups.

Protocol 4 consist in:

  1. Select provenance-specific variables in geochemical compositional data (CoDa) and ordinal petrographic data;
  2. Centred log-ratio transformation (clr) and transform to ranks;
  3. Extended Gower coefficient of dissimilarity, using Relative ranking difference (RRD);
  4. Apply Principal Coordinates Analysis (PCoA);
  5. Perform PERMANOVA & PERMDISP tests;

Last, search for outliers and re-do protocol excluding outliers.

NOTE: The initial procedures must be ran at least once before any protocol can be applied.