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  • event() fit a date event model.

  • predict_event() and predict_accumulation() estimates the event and accumulation dates of an assemblage.


event(object, dates, ...)

predict_event(object, data, ...)

predict_accumulation(object, data, ...)

# S4 method for data.frame,numeric
event(object, dates, rank = 10, cutoff = NULL, ...)

# S4 method for matrix,numeric
event(object, dates, rank = 10, cutoff = NULL, ...)

# S4 method for EventDate,missing
predict_event(object, margin = 1, level = 0.95)

# S4 method for EventDate,matrix
predict_event(object, data, margin = 1, level = 0.95)

# S4 method for EventDate,missing

# S4 method for EventDate,matrix
predict_accumulation(object, data)

# S4 method for EventDate
summary(object, ...)



An \(m \times p\) numeric matrix or a data.frame of count data (absolute frequencies).


A numeric vector of dates expressed in CE years (BCE years must be given as negative numbers). If named, the names must match the row names of object.


Further arguments to be passed to internal methods.


A numeric matrix or a data.frame of count data (absolute frequencies)for which to predict event and accumulation dates.


An integer specifying the number of CA factorial components to be use for linear model fitting (see details).


An integer giving the cumulative percentage of variance used to select CA factorial components for linear model fitting (see details). All compounds with a cumulative percentage of variance of less than the cutoff value will be retained. This argument is defunct: use rank instead.


A numeric vector giving the subscripts which the prediction will be applied over: 1 indicates rows, 2 indicates columns.


A length-one numeric vector giving the confidence level.



This is an implementation of the chronological modeling method proposed by Bellanger and Husi (2012, 2013).

Event and accumulation dates are density estimates of the occupation and duration of an archaeological site (Bellanger and Husi 2012, 2013). The event date is an estimation of the terminus post-quem of an archaeological assemblage. The accumulation date represents the "chronological profile" of the assemblage. According to Bellanger and Husi (2012), accumulation date can be interpreted "at best [...] as a formation process reflecting the duration or succession of events on the scale of archaeological time, and at worst, as imprecise dating due to contamination of the context by residual or intrusive material." In other words, accumulation dates estimate occurrence of archaeological events and rhythms of the long term.

This method relies on strong archaeological and statistical assumptions (see vignette("event")).


All results are rounded to zero decimal places (sub-annual precision does not make sense in most situations). You can change this behavior with options(kairos.precision = x) (for x decimal places).

Bellanger et al. did not publish the data supporting their demonstration: no replication of their results is possible. This implementation must be considered experimental and subject to major changes in a future release.


Bellanger, L. & Husi, P. (2013). Mesurer et modéliser le temps inscrit dans la matière à partir d'une source matérielle : la céramique médiévale. In Mesure et Histoire Médiévale. Histoire ancienne et médiévale. Paris: Publication de la Sorbonne, p. 119-134.

Bellanger, L. & Husi, P. (2012). Statistical Tool for Dating and Interpreting Archaeological Contexts Using Pottery. Journal of Archaeological Science, 39(4), 777-790. doi:10.1016/j.jas.2011.06.031 .

Bellanger, L., Tomassone, R. & Husi, P. (2008). A Statistical Approach for Dating Archaeological Contexts. Journal of Data Science, 6, 135-154.

Bellanger, L., Husi, P. & Tomassone, R. (2006). Une approche statistique pour la datation de contextes archéologiques. Revue de Statistique Appliquée, 54(2), 65-81.

Bellanger, L., Husi, P. & Tomassone, R. (2006). Statistical Aspects of Pottery Quantification for the Dating of Some Archaeological Contexts. Archaeometry, 48(1), 169-183. doi:10.1111/j.1475-4754.2006.00249.x .

Poblome, J. & Groenen, P. J. F. (2003). Constrained Correspondence Analysis for Seriation of Sagalassos Tablewares. In Doerr, M. & Apostolis, S. (eds.), The Digital Heritage of Archaeology. Athens: Hellenic Ministry of Culture.

See also

plot(), jackknife(), bootstrap()

Other dating methods: mcd()


N. Frerebeau


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