Rate of Change

Computes the rate of change from an aoristic analysis.

Usage

roc(object, ...)

# S4 method for class 'AoristicSum'
roc(object, n = 100)

Arguments

object

An AoristicSum object.

...

Currently not used.

n

A non-negative integer giving the number of replications (see details).

Value

A RateOfChange object.

References

Baxter, M. J. & Cool, H. E. M. (2016). Reinventing the Wheel? Modelling Temporal Uncertainty with Applications to Brooch Distributions in Roman Britain. Journal of Archaeological Science, 66: 120-27. doi:10.1016/j.jas.2015.12.007 .

Crema, E. R. (2012). Modelling Temporal Uncertainty in Archaeological Analysis. Journal of Archaeological Method and Theory, 19(3): 440-61. doi:10.1007/s10816-011-9122-3 .

See also

aoristic(), plot()

Other chronological analysis: aoristic(), apportion(), fit()

Author

N. Frerebeau

Examples

## Data from Husi 2022
data("loire", package = "folio")

## Get time range
loire_range <- loire[, c("lower", "upper")]

## Calculate aoristic sum (normal)
aorist_raw <- aoristic(loire_range, step = 50, weight = FALSE)
plot(aorist_raw, col = "grey")


## Calculate aoristic sum (weights)
aorist_weighted <- aoristic(loire_range, step = 50, weight = TRUE)
plot(aorist_weighted, col = "grey")


## Calculate aoristic sum (weights) by group
aorist_groups <- aoristic(loire_range, step = 50, weight = TRUE,
                          groups = loire$area)
plot(aorist_groups, flip = TRUE, col = "grey")

image(aorist_groups)


## Rate of change
roc_weighted <- roc(aorist_weighted, n = 30)
plot(roc_weighted)


## Rate of change by group
roc_groups <- roc(aorist_groups, n = 30)
plot(roc_groups, flip = TRUE)