Fits a PLSR model with the SIMPLS algorithm.
simpls.fit(X, Y, ncomp, center = TRUE, stripped = FALSE, ...)
A list containing the following components is returned:
an array of regression coefficients for 1, ...,
ncomp
components. The dimensions of coefficients
are
c(nvar, npred, ncomp)
with nvar
the number of X
variables and npred
the number of variables to be predicted in
Y
.
a matrix of scores.
a matrix of loadings.
a matrix of Y-scores.
a matrix of Y-loadings.
the projection matrix used to convert X to scores.
a vector of means of the X variables.
a vector of means of the Y variables.
an
array of fitted values. The dimensions of fitted.values
are
c(nobj, npred, ncomp)
with nobj
the number samples and
npred
the number of Y variables.
an array of
regression residuals. It has the same dimensions as fitted.values
.
a vector with the amount of X-variance explained by each component.
Total variance in X
.
If stripped
is TRUE
, only the components coefficients
,
Xmeans
and Ymeans
are returned.
a matrix of observations. NA
s and Inf
s are not
allowed.
a vector or matrix of responses. NA
s and Inf
s are
not allowed.
the number of components to be used in the modelling.
logical, determines if the \(X\) and \(Y\) matrices are mean centered or not. Default is to perform mean centering.
logical. If TRUE
the calculations are stripped as
much as possible for speed; this is meant for use with cross-validation or
simulations when only the coefficients are needed. Defaults to
FALSE
.
other arguments. Currently ignored.
Ron Wehrens and Bjørn-Helge Mevik
This function should not be called directly, but through the generic
functions plsr
or mvr
with the argument
method="simpls"
. SIMPLS is much faster than the NIPALS algorithm,
especially when the number of X variables increases, but gives slightly
different results in the case of multivariate Y. SIMPLS truly maximises the
covariance criterion. According to de Jong, the standard PLS2 algorithms
lie closer to ordinary least-squares regression where a precise fit is
sought; SIMPLS lies closer to PCR with stable predictions.
de Jong, S. (1993) SIMPLS: an alternative approach to partial least squares regression. Chemometrics and Intelligent Laboratory Systems, 18, 251--263.
mvr
plsr
pcr
kernelpls.fit
widekernelpls.fit
oscorespls.fit