4. Pre-treatment options
Standardising samples
How the data are treated, prior to computation of a resemblance matrix (e.g. similarities), can h...
Stats to worksheet
Several of the routines in PRIMER 7 also incorporate a check box for sending summary statistics u...
Standardising species
Pre-treatment>Standardise can also be used to standardise the matrix on the variables axis, e.g. ...
Transforming (overall)
Transformation is usually applied to all the entries in an assemblage matrix of counts, biomass, ...
Shade plots to aid choice of transform
A major new feature in PRIMER 7 is the large number of additional plotting routines, one of the c...
Transforming abiotic variables
Transformations may be appropriate for environmental variables too, though usually for a differen...
Draftsman, histogram & multi-plots
Temporarily deselect the Distance (as in Section 3), and run Plots>Draftsman Plot on the other 9 ...
Transforming (individual)
Both the Draftsman and Histogram Plots show that several of the Ekofisk abiotic variables are hig...
Normalising variables
It is typical of a suite of physico-chemical variables (or biomarkers, water-quality indices etc)...
Dispersion weighting of species
When variables are on different measurement scales, there is little viable alternative to normali...
(Fal estuary copepods)
Sediment copepod assemblages (and other fauna) from five creeks of the Fal estuary, SW England, w...
Other variable weighting
There are other cases in which variables (species) might need prior weighting, e.g. when a specie...
Mixed data types
Another example might be in attempting to reconcile two different types of data in the same matri...
Variability weighting
Pre-treatment>Variability Weighting is a new option in PRIMER 7, which bears similarities to the ...
(Biomarkers for N Sea flounder)
The directory C:\Examples v7\N Sea biomarkers holds a data sheet N Sea flounder biomarkers(.pri) ...
Cumulating samples
The remaining option on the Pre-treatment menu is Cumulate samples, which successively adds up th...
(Particle sizes for Danish sediments)
Sediment particle size data from 6 size ranges at 3 sites (A, B, C), at 2 depths (2m and 5m), and...
Surface plots
The smoothing effect can best be seen by Plots>Surface Plot of both Data1 and Data2 sheets – a fu...