kdffreq: Fire frequency using kernel density

Description

Computes paleo-fire frequency for a set of fire events using a gaussian kernel density estimation procedure based on a defined bandwidth (see Mudelsee 2004 for details). Pseudo-replicated values are used to correct for edge bias, equivalent to "minimum slope" correction in Mann (2004).

Usage

kdffreq(fevent, up = NULL, lo = NULL, bandwidth = NULL, nbboot = NULL, alpha = NULL)

Arguments

fevent

Numeric vector, set of dates

Numeric, upper age for fire frequnecy calculus

Numeric, lower age for fire frequnecy calculus

bandwidth

Numeric, bandwidth in years, or character for automatic bandwidth calculation (e.g. "bw.ucv" for unbiased cross validation) see bandwidth for details

nbboot

Numeric, number of bootstrap replicates

alpha

Numeric, confidence interval (default 0.01)

Value

ff data.frame, with fire frequency, bandwidth and CIs

References

Mann, M. E. (2004). On smoothing potentially non-stationary climate time series. Geophysical Research Letters, 31(7). Mudelsee, M., Börngen, M., Tetzlaff, G., & Grünewald, U. (2004). Extreme floods in central Europe over the past 500 years: Role of cyclone pathway “Zugstrasse Vb”. Journal of Geophysical Research: Atmospheres (1984–2012), 109(D23).

Examples

Run this code


set.seed(123)
 fevent=c(round(abs(rnorm(20,mean=7,sd=5))*1000),round(abs(rnorm(10,mean=8,sd=1))*1000))

 ff=kdffreq(fevent,bandwidth = 1000, nbboot=10)