RMRAINGEN (version 1.0)

dw.spell: It calculates dry/wet spell duration.

Description

It calculates dry/wet spell duration.

Usage

dw.spell(data, valmin = 0.5, origin = "1961-1-1", extract = NULL, month = 1:12)

Arguments

data

data frame R object containing daily precipitation time series for several gauges (one gauge time series per column).

valmin

threshold precipitation value [mm] for wet/dry day indicator.

origin

character string "yyyy-mm-dd" indicated the date of the first row of "data".

extract

string charecter referred to the state to be extracted, eg. "dry" or "wet"

month

integer vectors containing the considered months. Default is 1:12 (all the year).

Value

Function returns a list of data frames containing the spell length expressed in days

Examples

library(RMRAINGEN)


data(trentino)

year_min <- 1961
year_max <- 1990

period <- PRECIPITATION$year>=year_min & PRECIPITATION$year<=year_max
station <- names(PRECIPITATION)[!(names(PRECIPITATION) %in% c("day","month","year"))]
prec_mes <- PRECIPITATION[period,station]

## removing nonworking stations (e.g. time series with NA)
accepted <- array(TRUE,length(names(prec_mes)))
names(accepted) <- names(prec_mes)
for (it in names(prec_mes)) {
		 accepted[it]  <- (length(which(!is.na(prec_mes[,it])))==length(prec_mes[,it]))
}

prec_mes <- prec_mes[,accepted]
## the dateset is reduced!!!
prec_mes <- prec_mes[,1:3]

origin <- paste(year_min,1,1,sep="-")
dw.spell <- dw.spell(prec_mes,origin=origin)
dw.spell.dry <- dw.spell(prec_mes,origin=origin,extract="dry")

hist(dw.spell.dry$T0001$spell_length)