mescla.prep.transform¶
Standardisation of water chemistry prior to eigen-analysis.
EMMA is run on standardised concentrations so that solutes with large absolute values (electrical conductivity, bicarbonate) do not swamp trace tracers – this is what makes the eigen-analysis a correlation-matrix PCA rather than a covariance-matrix one.
The single most damaging implementation bug in EMMA is standardising candidate
end-members with their own mean and standard deviation instead of the mixed
samples’. Standardizer exists so that cannot happen: it is fitted once, on
the samples, and then applied to everything else.
Classes
Z-score standardiser fitted on mixed samples and reused for everything else. |