fast_ICA: Wrapper for FastICA method for Independent Component Analysis...

In bnicenboim/eeguana: Flexible Manipulation of EEG Data

Wrapper for FastICA method for Independent Component Analysis from fastICA package

Description

fast_ICA() is a wrapper for fastICA::fastICA, with different defaults (runs in C, maximum iteration = 1000, tolerance = 1e-04, verbose), and that throws a warning in case of non-convergence. It returns an estimated unmixing matrix W (equivalent to the original K %*% W), and the mixing matrix A, consistent with the formulation X= S %*% A, and X %*% W = S where X is the matrix of data with N_samples by N_channels, and S is a matrix of sources with N_samples by N_sources. They are meant to be used with eeg_ica().

Usage

fast_ICA(
  X,
  n.comp = NULL,
  alg.typ = "parallel",
  fun = "logcosh",
  alpha = 1,
  method = "C",
  row.norm = FALSE,
  maxit = 1000,
  tol = 1e-06,
  w.init = NULL
)

Arguments

X	A matrix or data frame.
n.comp	number of components to be extracted
alg.typ	if alg.typ == "parallel" the components are extracted simultaneously (the default). if alg.typ == "deflation" the components are extracted one at a time.
fun	the functional form of the G function used in the approximation to neg-entropy (see ‘details’).
alpha	constant in range [1, 2] used in approximation to neg-entropy when fun == "logcosh"
method	if method == "R" then computations are done exclusively in R (default). The code allows the interested R user to see exactly what the algorithm does. if method == "C" then C code is used to perform most of the computations, which makes the algorithm run faster. During compilation the C code is linked to an optimized BLAS library if present, otherwise stand-alone BLAS routines are compiled.
row.norm	a logical value indicating whether rows of the data matrix X should be standardized beforehand.
maxit	maximum number of iterations to perform.
tol	a positive scalar giving the tolerance at which the un-mixing matrix is considered to have converged.
w.init	Initial un-mixing matrix of dimension c(n.comp, n.comp). If NULL (default) then a matrix of normal r.v.'s is used.

Value

A list with the unmixing matrix W and the mixing matrix A.

See Also

Other ica methods: fICA, ica_matrix_lst()

bnicenboim/eeguana documentation built on March 16, 2024, 7:21 a.m.