Displaying 20 results from an estimated 5000 matches similar to: "(no subject)"
2003 Feb 22
4
faraway tutorial: cryptic command to newbie
I am just about working through Faraways excellent tutorial "practical
regression and ANOVA using R"
on page 24 he makes the x matrix:
x <- cbind(1,gala[,-c(1,2)])
how can I understand this gala[,-c(1,2)])... I couldn't find an
explanation of such "c-like" abbreviations anywhere.
thanks for a hint.
another problem: I couldn't load the faraway library, using the
2003 May 22
1
faraway package installation failed (PR#3076)
Full_Name: José Otero
Version: Version 1.5.0 (2002-04-29)
OS: Redhat 7.3
Submission from: (NULL) (192.187.16.164)
Hi:
Installation of package faraway
as root, from tarbal:
R CMD INSTALL ./faraway.tar.gz
ERROR: cannot extract package from './faraway.tar.gz'
idem, from zipped package:
R CMD INSTALL faraway.zip
gzip: faraway.zip has more than one entry--rest ignored
ERROR: cannot
2001 Jul 08
1
predict.lm(...., se=T), with 1-column model matrix (PR#1018)
# r-bugs@r-project.org
The problem occurs when the model matrix has a single
column.
> elastic <- data.frame(stretch=c(46,54,48,50,44,42,52),
distance=c(183,217,189,208,178,150,249))
> elastic.lm <- lm(distance ~ -1 + stretch, data=elastic)
> predict(elastic.lm,se=T)
Error in XRinv^2 %*% rep(res.var, p) : non-conformable arguments
The fix is to replace
XRinv <-
2009 Feb 12
0
Sign differences amoung QR solutions.
I was noticing mainly sign differences amoung the solutions to QR decomposition. For example R:
> x <- matrix(c(12,-51,4,6,167,-68,-4,24,-41),nrow=3,byrow=T)
> x
[,1] [,2] [,3]
[1,] 12 -51 4
[2,] 6 167 -68
[3,] -4 24 -41
> r <- qr(x)
> r$qr
[,1] [,2] [,3]
[1,] -14.0000000 -21.0000000 14
[2,] 0.4285714 -175.0000000 70
[3,]
2002 Oct 25
2
source output differs from console output
Dear R-help,
I would like to be able to run the following code sequence as a source
routine.
If I paste it into R via the clipboard it works as expected, but if I source
the code instead then the last 3 statements fail.
I've also tried writing to the file in place of the sink sequence, but that
also hits a snag. R 1.6, w98e2, dfr is a data frame containing the content
of Julian
2009 Jun 17
3
Matrix inversion-different answers from LAPACK and LINPACK
Hello.
I am trying to invert a matrix, and I am finding that I can get different
answers depending on whether I set LAPACK true or false using "qr". I had
understood that LAPACK is, in general more robust and faster than LINPACK,
so I am confused as to why I am getting what seems to be invalid answers.
The matrix is ostensibly the Hessian for a function I am optimizing. I want
to get
2019 Aug 13
0
behaviour and documentation of qr.solve
Greetings,
In my opinion the documentation or behaviour of qr.solve, qr.coef, qr.resid, and qr.fitted is not easily comprehensible and unfortunate.
We all know that a linear system Ax=b can have 0, one or infinitely many solutions. To treat all these cases uniformly we can rephrase the problem
as
x = argmin_u||Au-b||,
1998 Jun 04
1
aov
R developers,
Last week I asked several questions which I think I can now answer
myself in large part.
>
> Q 1) Is aov supposed to avoid qr decomposition and matrix inversion?
> In S it is claimed to be faster than lm() for large datasets. Is
> that due to avoidance of qr()?
> (My main goal is to get the Error strata working.)
My use of matrix
2005 Nov 02
0
Bugs/issues with model.tables() (PR#8275)
Based on what follows, the most favourable construction is that
the documentation, by failing to say that the function should be
used only for completely balanced designs, is deficient. Even
for such designs, there is a bug that needs correction. The
discussion is lengthy because I think it important to document,
at least wrt effects and means, exactly what model.tables()
does.
My preference is
2007 Apr 19
0
qr.coef: permutes dimnames; inserts NA; promises minimum-length (PR#9623)
Full_Name: Christian Brechbuehler
Version: 2.4.1 Patched (2007-03-25 r40917)
OS: Linux 2.6.15-27-adm64-xeon; Ubuntu 6.06.1 LTS
Submission from: (NULL) (24.61.47.236)
Splus and R have different ideas about what qr.coef(qr()) should return,
which is fine... but I believe that R has a bug in that it is not
internally consistent, and another separate bug in the documentation.
In particular, on
2000 May 01
1
solve vs. qr.solve
> Date: Mon, 1 May 2000 16:25:11 +0200 (CEST)
> From: gb <gb at stat.umu.se>
>
> On 1 May 2000, Douglas Bates wrote:
> > gb <gb at stat.umu.se> writes:
> >
> > > How about 'Ainv <- qr.solve(A)'?
> > >
> > > I happened to read the help page for 'qr.solve' the other day, and there I
> > > found that
2007 May 01
1
(PR#9623) qr.coef: permutes dimnames; inserts NA; promises
On Thu, 19 Apr 2007, brech at delphioutpost.com wrote:
> Full_Name: Christian Brechbuehler
> Version: 2.4.1 Patched (2007-03-25 r40917)
> OS: Linux 2.6.15-27-adm64-xeon; Ubuntu 6.06.1 LTS
> Submission from: (NULL) (24.61.47.236)
>
>
> Splus and R have different ideas about what qr.coef(qr()) should return,
> which is fine... but I believe that R has a bug in that it is not
2004 Aug 06
1
Encrypted password problem with icecast 1.3.11
Hi All,
I have recently downloaded and compiled IceCast 1.3.11 with the crypt option
turned on. Once I did this I have not been able to access the ADMIN console
through telnet. I got the latest version of mkpasswd from CVS and compiled
it. I have included the encrypted version of the password into the
configuration file and then started icecast.
Am I doing something wrong? One thing that
2006 Oct 06
1
problem using libao on OSX 10.4
I installed fink and now I have the /sw/lib, however that didn't fix
my problem. I went as far as to take out the -
Ddlsym=dlsym_auto_underscore out of the configuration files. Now
however the libao package won't build at all and yips about this:
[ukiel:/MP3/OGG/libao-0.8.6] wind% make
Making all in src
Making all in plugins
Making all in oss
make[3]: Nothing to be done for
2006 Oct 03
1
New versions of Matrix and lme4 packages for R-2.4.0
Versions 0.9975-1 of the Matrix and lme4 packages will soon be available on
CRAN for use with R version 2.4.0 or later.
Purpose of the packages:
The Matrix package provides S4 classes and methods for sparse
and dense matrices. The lme4 package provides functions for fitting
and assessing linear or generalized linear mixed effects models (also
called multilevel models). Like the Matrix package,
2006 Oct 03
1
New versions of Matrix and lme4 packages for R-2.4.0
Versions 0.9975-1 of the Matrix and lme4 packages will soon be available on
CRAN for use with R version 2.4.0 or later.
Purpose of the packages:
The Matrix package provides S4 classes and methods for sparse
and dense matrices. The lme4 package provides functions for fitting
and assessing linear or generalized linear mixed effects models (also
called multilevel models). Like the Matrix package,
2012 Sep 07
1
Suggest adding a 'pivot' argument to qr.R
I suggest adding a 'pivot' argument to qr.R, to obtain columns in the
same order as the original x, so that
a <- qr(x)
qr.Q(a) %*% qr.R(a, pivot=TRUE)
returns x.
--------------------------------------------------
# File src/library/base/R/qr.R
qr.R <- function(qr, complete = FALSE, pivot = FALSE)
{
# Args:
# qr: a QR decomposition, produced by qr()
# complete:
2004 Mar 01
0
se.contrast ....too hard??? .... Too easy????? .....too trivial???? ...... Too boring.....too????????
Hi all,
Regular and avid readers of this column will know that Don Driscoll and
I have recently posted two messages requesting assistance concerning an
apparent failure of "se.contrast" to produce an se for a contrast. So
far, an ominous silence rings in our ears, but read on Gentle Reader,
and see if even the machinations of "debug" doesn't stimulate you to
respond with a
2011 Nov 21
0
Suggested improvement for src/library/base/man/qraux.Rd
Here is a modified version of qraux.Rd, an edited version of
R-2.14.0/src/library/base/man/qraux.Rd
This gives some details and an example for the case of pivoting.
In this case, it is not true that X = QR; rather X[, pivot] = QR.
It may save some other people bugs and time to have this information.
Tim Hesterberg
--------------------------------------------------
% File
2004 Mar 05
1
row-echelon form (was no subject)
I think one needs an LU decomposition rather than QR.
However, I couldn't find anything off the shelf to do
an LU, other than learning that determinant() now
uses LU instead of QR or SVD, so the code to do it must
be in there for those that want it.
You'll probably need to divide rows of U by the first
entry if you insist on the unique reduced REF.
However, I can't see any reason