spell: Spell statistics

In metno/esd: Climate analysis and empirical-statistical downscaling (ESD) package for monthly and daily data

Spell statistics

Description

Statistics of spell durations (consecutive wet and dry days), e.g. dry and wet periods or duration of extremes. Similar functions include: count returns a count of cases with values over s threshold value. exceedance estimates statistics for peak-over-threshold, and nevents returns the number of events with exceeding values (e.g. the number of rainy days X > 1 mm/day). wetfreq returns the wet-day frequency (a fraction) and wetmean returns the wet-day mean. CDD: Cooling degree day GDD: Growing degree days (http://en.wikipedia.org/wiki/Growing_degree-day) HDD: Heating degree day qqgeom produces a quantile-quantile plot of streak statistics comparing the empirical quantiles with the distribution function quantiles (see qgeom).

Usage

spell(x, threshold, ...)

Arguments

x	station or field object
threshold	threshold value
upper	upper limit for maximum length - ignore any above this because they are likely erronoeus
higher	argument of count, if TRUE: count values above threshold, FALSE: count values below threshold
fraction	TRUE: divide the number of counts by number of samples
FUN	function

Value

Station or field objects

See Also

hotsummerdays coldwinterdays coldspells heatwavespells nwetdays plot

Examples

# Example 1 : 
data(bjornholt)
x <- spell(bjornholt, threshold=.1)
plot(x, new=FALSE)

# Example 2 :
x.ann <- annual(x, FUN="max")
plot(x.ann, plot.type="multiple", new=FALSE)

# Quantile-quantile plot for the duration of dry and wet spells
# comparing their distribution against the geometric distribution
qqgeom(bjornholt, treshold=1, pois=TRUE)

#' # Growing degree days:
data(ferder)
plot(annual(ferder,FUN='GDD'), new=FALSE)

metno/esd documentation built on Sept. 9, 2024, 5:07 a.m.