DTRRef {ClimProjDiags}

Diurnal temperature range of multidimensional arrays

Description

This function computes the mean diurnal temperature range (tmax - tmin).

Usage

DTRRef(
  tmax,
  tmin,
  by.seasons = TRUE,
  dates = NULL,
  timedim = NULL,
  calendar = NULL,
  na.rm = TRUE,
  ncores = NULL
)

Arguments

tmax

A numeric multidimensional array containing daily maximum temperature.

tmin

A numeric multidimensional array containing daily minimum temperature.

by.seasons

If TRUE (by default), the DTR is computed for each season (December-January-February, March-April-May, June-July-August and September-October-November) seperately. If FALSE is specified, the montly mean DTR is computed.

dates

A vector of dates with a calendar attributes. If NULL (by default), the 'time' attributes of parameter 'tmax' and 'tmin' are considered.

timedim

An integer number indicating the position of the time dimension in the parameters tmax and tmin. If NULL (by default), the dimension called 'time' in parameter tmax and tmin is considered as time dimension.

calendar

A character indicating the calendar type.

na.rm

A logical indicating whether missing values should be removed. If na.rm is FALSE an NA value in any of the arguments will cause a value of NA to be returned, otherwise (TRUE by default) NA values are ignored.

ncores

The number of cores to be used when computing the index.

Details

The function returns a reordered array with 'time' dimension in the first position in the dtr.ref label.

Value

A list of length 2:

• $dtr.ref, an array with the same dimensions as the input data, but with the time dimension reduce from daily to monthly or seasonal resolution depending on the selected resolution in by.season.

• $season, a vector of the season or months corresponding to the resolution selected in by.season.

Examples

##Exmaple with synthetic data:
tmax <- 1:(2 * 3 * 365 * 1)
dim(tmax) <- c(lon = 2, lat = 3, time = 365, model = 1)
tmin <- (1:(2 * 3 * 365 * 1))-1
dim(tmin) <- c(lon = 2, lat = 3, time = 365, model = 1)
time <- seq.Date(as.Date("1900-01-01", format = "%Y-%d-%m"), 
                as.Date("1900-31-12", format = "%Y-%d-%m"), 1)
time <- as.POSIXct(time, tz = "CET")
metadata <- list(time = list(standard_name = 'time', long_name = 'time', 
                            calendar = 'noleap',
                            units = 'days since 1970-01-01 00:00:00', 
                            prec = 'double', 
                            dim = list(list(name ='time', unlim = FALSE))))
attr(time, "variables") <- metadata
attr(tmax, 'Variables')$dat1$time <- time
attr(tmax, 'Variables')$common[[2]]$dim[[3]]$len = length(time)
attr(tmax, 'Variables')$common[[2]]$dim[[3]]$vals <- time
attr(tmin, 'Variables')$dat1$time <- time
attr(tmin, 'Variables')$common[[2]]$dim[[3]]$len = length(time)
attr(tmin, 'Variables')$common[[2]]$dim[[3]]$vals <- time

a <- DTRRef(tmax, tmin, by.seasons = FALSE, ncores = NULL)
str(a)

tmax <- 1:(2 * 3 * 365 * 1)
dim(tmax) <- c(2, 3, 365)
tmin <- (1:(2 * 3 * 365 * 1))-1
dim(tmin) <- c(2, 3, 365)

a <- DTRRef(tmax, tmin, by.seasons = FALSE, dates = time,  timedim = 3, 
           ncores = NULL)
str(a)