CST_Anomaly {CSTools}

Anomalies relative to a climatology along selected dimension with or without cross-validation

Description

This function computes the anomalies relative to a climatology computed along the selected dimension (usually starting dates or forecast time) allowing the application or not of crossvalidated climatologies. The computation is carried out independently for experimental and observational data products.

Usage

CST_Anomaly(
  exp = NULL,
  obs = NULL,
  dim_anom = "sdate",
  cross = FALSE,
  memb_dim = "member",
  memb = TRUE,
  dat_dim = c("dataset", "member"),
  filter_span = NULL,
  ftime_dim = "ftime",
  ncores = NULL
)

Arguments

exp

An object of class s2dv_cube as returned by CST_Start function, containing the seasonal forecast experiment data in the element named $data.

obs

An object of class s2dv_cube as returned by CST_Start function, containing the observed data in the element named $data.

dim_anom

A character string indicating the name of the dimension along which the climatology will be computed. The default value is 'sdate'.

cross

A logical value indicating whether cross-validation should be applied or not. Default = FALSE.

memb_dim

A character string indicating the name of the member dimension. It must be one dimension in 'exp' and 'obs'. If there is no member dimension, set NULL. The default value is 'member'.

memb

A logical value indicating whether to subtract the climatology based on the individual members (TRUE) or the ensemble mean over all members (FALSE) when calculating the anomalies. The default value is TRUE.

dat_dim

A character vector indicating the name of the dataset and member dimensions. If there is no dataset dimension, it can be NULL. The default value is "c('dataset', 'member')".

filter_span

A numeric value indicating the degree of smoothing. This option is only available if parameter cross is set to FALSE.

ftime_dim

A character string indicating the name of the temporal dimension where the smoothing with 'filter_span' will be applied. It cannot be NULL if 'filter_span' is provided. The default value is 'ftime'.

ncores

An integer indicating the number of cores to use for parallel computation. The default value is NULL. It will be used only when 'filter_span' is not NULL.

Value

A list with two S3 objects, 'exp' and 'obs', of the class 's2dv_cube', containing experimental and date-corresponding observational anomalies, respectively. These 's2dv_cube's can be ingested by other functions in CSTools.

Author(s)

Perez-Zanon Nuria, [e-mail]

Pena Jesus, [e-mail]

See Also

Ano_CrossValid, Clim and CST_Start

Examples

mod <- 1 : (2 * 3 * 4 * 5 * 6 * 7)
dim(mod) <- c(dataset = 2, member = 3, sdate = 4, ftime = 5, lat = 6, lon = 7)
obs <- 1 : (1 * 1 * 4 * 5 * 6 * 7)
dim(obs) <- c(dataset = 1, member = 1, sdate = 4, ftime = 5, lat = 6, lon = 7)
lon <- seq(0, 30, 5)
lat <- seq(0, 25, 5)
coords <- list(lon = lon, lat = lat)
exp <- list(data = mod, coords = coords)
obs <- list(data = obs, coords = coords)
attr(exp, 'class') <- 's2dv_cube'
attr(obs, 'class') <- 's2dv_cube'

anom <- CST_Anomaly(exp = exp, obs = obs, cross = FALSE, memb = TRUE)