Independance

eppm(object, ...) pvi(object, ...) # S4 method for CountMatrix eppm(object) # S4 method for CountMatrix pvi(object)

object | A CountMatrix object. |
---|---|

... | Currently not used. |

A `numeric`

matrix.

Computes for each cell of a numeric matrix one of the following statistic.

This positive difference from the column mean percentage (in french "écart
positif au pourcentage moyen", EPPM) represents a deviation from the
situation of statistical independence. As independence can be interpreted as
the absence of relationships between types and the chronological order of
the assemblages, `EPPM`

is a useful graphical tool to explore
significance of relationship between rows and columns related to
seriation (Desachy 2004).

`PVI`

is calculated for each cell as the percentage to the column
theoretical independence value: `PVI`

greater than \(1\) represent
positive deviations from the independence, whereas `PVI`

smaller than
\(1\) represent negative deviations (Desachy 2004).

The `PVI`

matrix allows to explore deviations from independence
(an intuitive graphical approach to \(\chi^2\)),
in such a way that a high-contrast matrix has quite significant deviations,
with a low risk of being due to randomness (Desachy 2004).

Desachy, B. (2004). Le sériographe EPPM: un outil informatisé de sériation
graphique pour tableaux de comptages. *Revue archéologique de
Picardie*, 3(1), 39-56.
DOI: 10.3406/pica.2004.2396.

plot_ford, plot_heatmap, seriate_rank

Other statistics:
`refine`

,
`test_diversity()`

,
`test_fit()`

N. Frerebeau