s2dverification (version 2.4.0)

EnoNew: Computes Effective Sample Size Following Guemas et al, BAMS, 2013b

Description

This function computes the equivalent number of independent data in the xdata array following the method described in Guemas V., Auger L., Doblas-Reyes F., JAMC, 2013. The method relies on the Trenberth (1984) formula combined with a reduced uncertainty of the estimated autocorrelation function compared to the original approach.

Usage

EnoNew(xdata, detrend = FALSE, filter = FALSE)

Examples

# See examples on Load() to understand the first lines in this example
  configfile <- paste0(tempdir(), '/sample.conf')
ConfigFileCreate(configfile, confirm = FALSE)
c <- ConfigFileOpen(configfile)
c <- ConfigEditDefinition(c, 'DEFAULT_GRID', 'r20x10', confirm = FALSE)
c <- ConfigEditDefinition(c, 'DEFAULT_VAR_MIN', '-1e19', confirm = FALSE)
c <- ConfigEditDefinition(c, 'DEFAULT_VAR_MAX', '1e19', confirm = FALSE)
c <- ConfigAddVar(c, '2d', 'tos')
data_path <- system.file('sample_data', package = 's2dverification')
exp_data_path <- paste0(data_path, '/model/$EXP_NAME$')
obs_data_path <- paste0(data_path, '/$OBS_NAME$')
c <- ConfigAddEntry(c, 'experiments', 'file-per-startdate',
     dataset_name = 'experiment', var_name = 'tos', main_path = exp_data_path,
     file_path = '$STORE_FREQ$_mean/$VAR_NAME$_3hourly/$VAR_NAME$_$START_DATE$.nc')
c <- ConfigAddEntry(c, 'observations', 'file-per-month',
     dataset_name = 'observation', var_name = 'tos', main_path = obs_data_path,
     file_path = '$STORE_FREQ$_mean/$VAR_NAME$/$VAR_NAME$_$YEAR$$MONTH$.nc')
ConfigFileSave(c, configfile, confirm = FALSE)

# Now we are ready to use Load().
startDates <- c('19851101', '19901101', '19951101', '20001101', '20051101')
sampleData <- Load('tos', c('experiment'), c('observation'), startDates,
                   leadtimemin = 1, leadtimemax = 4, output = 'lonlat',
                   latmin = 27, latmax = 48, lonmin = -12, lonmax = 40,
                   configfile = configfile)
  startDates <- c('19851101', '19901101', '19951101', '20001101', '20051101')
sampleData <- s2dverification:::.LoadSampleData('tos', c('experiment'),
                                                c('observation'), startDates,
                                                leadtimemin = 1,
                                                leadtimemax = 4,
                                                output = 'lonlat',
                                                latmin = 27, latmax = 48,
                                                lonmin = -12, lonmax = 40)
eno <- EnoNew(sampleData$mod[1, 1, , 1, 2, 3])
print(eno)