[Rcpp-commits] r3216 - pkg/RcppEigen/man
noreply at r-forge.r-project.org
noreply at r-forge.r-project.org
Sat Oct 22 00:48:32 CEST 2011
Author: dmbates
Date: 2011-10-22 00:48:32 +0200 (Sat, 22 Oct 2011)
New Revision: 3216
Modified:
pkg/RcppEigen/man/fastLm.Rd
Log:
Align documentation with new code.
Modified: pkg/RcppEigen/man/fastLm.Rd
===================================================================
--- pkg/RcppEigen/man/fastLm.Rd 2011-10-21 22:47:49 UTC (rev 3215)
+++ pkg/RcppEigen/man/fastLm.Rd 2011-10-21 22:48:32 UTC (rev 3216)
@@ -34,7 +34,10 @@
\item{method}{an integer scalar with value 0 for the column-pivoted QR
decomposition, 1 for the unpivoted QR decomposition, 2 for the LLT
- Cholesky, 3 for the LDLT Cholesky. Default is zero.}
+ Cholesky, 3 for the LDLT Cholesky, 4 for the Jacobi singular value
+ decomposition (SVD) and 5 for a method based on the
+ eigenvalue-eigenvector decomposition of
+ \eqn{\mathbf{X}^\prime\mathbf{X}}{X'X}. Default is zero.}
\item{\dots}{not used}
}
@@ -49,9 +52,11 @@
a linear model fit, offering both a default and a formula interface as
well as \code{print}, \code{summary} and \code{predict} methods.
- Internally the \code{fastLm} function uses a QR decomposition with
- column pivots, which is a rank-revealing decomposition, so that it can
- handle rank-deficient cases effectively.
+ Internally the \code{fastLm} function, by default, uses a QR
+ decomposition with column pivots, which is a rank-revealing
+ decomposition, so that it can handle rank-deficient cases
+ effectively. Other methods for determining least squares solutions
+ are available according to the value of the \code{method} argument.
An example of the type of situation requiring extra care in checking
for rank deficiency is a two-way layout with missing cells (see the
@@ -64,13 +69,14 @@
\item{coefficients}{a vector of coefficients}
\item{rank}{a scalar denoting the computed rank of the model matrix}
\item{df.residual}{a scalar denoting the degrees of freedom in the model}
- \item{stderr}{a vector of the (estimated) standard errors of the coefficient estimates}
+ \item{stderr}{a vector of the standard errors of the coefficient estimates}
\item{s}{a numeric scalar - the root mean square for residuals}
\item{residuals}{the vector of residuals}
\item{fitted.values}{the vector of fitted value}
- \item{Rinv}{the inverse of the upper-left r by r portion of matrix R
- from the QR decomposition}
\item{perm}{the 0-based permutation vector from the QR decomposition}
+ \item{unsc}{the unscaled variance-covariance matrix. This is the
+ inverse (or pseudo-inverse in the rank-deficient case when using a
+ rank-revealing decomposition) of \eqn{\mathbf{X}^\prime\mathbf{X}}{X'X}.}
\code{fastLm} returns a richer object which also includes the
call argument similar to the \code{\link{lm}} or
@@ -85,8 +91,6 @@
data(trees, package="datasets")
mm <- cbind(1, log(trees$Girth)) # model matrix
y <- log(trees$Volume) # response
- crossprod(mm)
- .Call("crossprod", mm, PACKAGE="RcppEigen")
## bare-bones direct interface
flm <- fastLmPure(mm, y)
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