climdex.pcic (version 1.1-11)

climdex.csdi: Cold Spell Duration Index

Description

This function computes the climdex index CSDI.

Usage

climdex.csdi(ci, spells.can.span.years = FALSE)

Arguments

ci

Object of type climdexInput.

spells.can.span.years

Whether to allow spells of dry/wet days to span years.

Value

A vector containing the value of the index for each year.

Details

This function takes a climdexInput object as input and computes the climdex index CSDI (Cold Spell Duration Index).

The cold spell duration index is defined as the number of days each year which are part of a "cold spell". A "cold spell" is defined as a sequence of 6 or more days in which the daily minimum temperature is below the 10th percentile of daily minimum temperature for a 5-day running window surrounding this day during the baseline period.

The spells.can.span.years option specifies whether spells can cross year boundaries -- i.e., span years. The default for this is the same as fclimdex.

References

http://etccdi.pacificclimate.org/list_27_indices.shtml

See Also

climdexInput.raw, climdexInput.csv, threshold.exceedance.duration.index.

Examples

# NOT RUN {
library(PCICt)

## Create a climdexInput object from some data already loaded in and
## ready to go.

## Parse the dates into PCICt.
tmax.dates <- as.PCICt(do.call(paste, ec.1018935.tmax[,c("year",
"jday")]), format="%Y %j", cal="gregorian")
tmin.dates <- as.PCICt(do.call(paste, ec.1018935.tmin[,c("year",
"jday")]), format="%Y %j", cal="gregorian")
prec.dates <- as.PCICt(do.call(paste, ec.1018935.prec[,c("year",
"jday")]), format="%Y %j", cal="gregorian")

## Load the data in.
ci <- climdexInput.raw(ec.1018935.tmax$MAX_TEMP,
ec.1018935.tmin$MIN_TEMP, ec.1018935.prec$ONE_DAY_PRECIPITATION,
tmax.dates, tmin.dates, prec.dates, base.range=c(1971, 2000))

## Create an annual timeseries of the cold spell duration index.
csdi <- climdex.csdi(ci)
# }