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mgcv (version 1.9-0)

Sl.inirep: Re-parametrizing model matrix X

Description

INTERNAL routine to apply initial Sl re-parameterization to model matrix X, or, if inverse==TRUE, to apply inverse re-parametrization to parameter vector or covariance matrix.

Usage

Sl.inirep(Sl,X,l,r,nt=1)
Sl.initial.repara(Sl, X, inverse = FALSE, both.sides = TRUE, cov = TRUE,
  nt = 1)

Value

A re-parametrized version of X.

Arguments

Sl

the output of Sl.setup.

X

the model matrix.

l

if non-zero apply transform (positive) or inverse transform from left. 1 or -1 of transform, 2 or -2 for transpose.

r

if non-zero apply transform (positive) or inverse transform from right. 1 or -1 of transform, 2 or -2 for transpose.

inverse

if TRUE an inverse re-parametrization is performed.

both.sides

if inverse==TRUE and both.sides==FALSE then the re-parametrization only applied to rhs, as appropriate for a choleski factor. If both.sides==FALSE, X is a vector and inverse==FALSE then X is taken as a coefficient vector (so re-parametrization is inverse of that for the model matrix).

cov

boolean indicating whether X is a covariance matrix.

nt

number of parallel threads to be used.

Author

Simon N. Wood <simon.wood@r-project.org>.