MultiEOF {CSTools}R Documentation

EOF analysis of multiple variables starting from an array (reduced version)

Description

This function performs EOF analysis over multiple variables, accepting in input an array with a dimension "var" for each variable to analyse. Based on Singular Value Decomposition. For each field the EOFs are computed and the corresponding PCs are standardized (unit variance, zero mean); the minimum number of principal components needed to reach the user-defined variance is retained. The function weights the input data for the latitude cosine square root.

Usage

MultiEOF(
  data,
  lon,
  lat,
  time,
  lon_dim = "lon",
  lat_dim = "lat",
  neof_max = 40,
  neof_composed = 5,
  minvar = 0.6,
  lon_lim = NULL,
  lat_lim = NULL
)

Arguments

data

A multidimensional array with dimension "var", containing the variables to be analysed. The other diemnsions follow the same structure as the "exp" element of a 's2dv_cube' object.

lon

Vector of longitudes.

lat

Vector of latitudes.

time

Vector or matrix of dates in POSIXct format.

lon_dim

String with dimension name of longitudinal coordinate

lat_dim

String with dimension name of latitudinal coordinate

neof_max

Maximum number of single eofs considered in the first decomposition

neof_composed

Number of composed eofs to return in output

minvar

Minimum variance fraction to be explained in first decomposition

lon_lim

Vector with longitudinal range limits for the calculation for all input variables

lat_lim

Vector with latitudinal range limits for the calculation for all input variables

Value

A list with elements $coeff (an array of time-varying principal component coefficients), $variance (a matrix of explained variances), eof_pattern (a matrix of EOF patterns obtained by regression for each variable).

Author(s)

Jost von Hardenberg - ISAC-CNR, j.vonhardenberg@isac.cnr.it

Paolo Davini - ISAC-CNR, p.davini@isac.cnr.it


[Package CSTools version 4.0.1 Index]