Displaying 20 results from an estimated 11000 matches similar to: "improved pairs.formula?"
2005 Aug 24
1
lm.ridge
Hello, I have posted this mail a few days ago but I did it wrong, I hope
is right now:
I have the following doubts related with lm.ridge, from MASS package. To
show the problem using the Longley example, I have the following doubts:
First: I think coefficients from lm(Employed~.,data=longley) should be
equal coefficients from lm.ridge(Employed~.,data=longley, lambda=0) why
it does not happen?
2011 Jan 04
5
scoping/non-standard evaluation issue
Dear r-devel list members,
On a couple of occasions I've encountered the issue illustrated by the
following examples:
--------- snip -----------
> mod.1 <- lm(Employed ~ GNP.deflator + GNP + Unemployed +
+ Armed.Forces + Population + Year, data=longley)
> mod.2 <- update(mod.1, . ~ . - Year + Year)
> all.equal(mod.1, mod.2)
[1] TRUE
>
> f <-
2011 Oct 09
1
strucchange Nyblom-Hansen Test?
I want to apply Nyblom-Hansen test with the strucchange package, but I don't
know how is the correct way and what is the difference between the following
two approaches (leeding to different results):
data("longley")
# 1. Approach:
sctest(Employed ~ Year + GNP.deflator + GNP + Armed.Forces, data = longley,
type = "Nyblom-Hansen")
#results in:
# Score-based CUSUM
2011 Aug 23
1
obtaining p-values for lm.ridge() coefficients (package 'MASS')
Dear all
I'm familiarising myself with Ridge Regressions in R and the following
is bugging me: How does one get p-values for the coefficients obtained
from MASS::lm.ridge() output (for a given lambda)? Consider the
example below (adapted from PRA [1]):
> require(MASS)
> data(longley)
> gr <- lm.ridge(Employed ~ .,longley,lambda = seq(0,0.1,0.001))
> plot(gr)
> select(gr)
2010 Feb 25
1
How to do: Correlation with "blocks" (or - "repeated measures" ?!) ?
Hello dear R help group,
I have the following setup to analyse:
We have about 150 subjects, and for each subject we performed a pair of
tests (under different conditions) 18 times.
The 18 different conditions of the test are complementary, in such a way so
that if we where to average over the tests (for each subject), we would get
no correlation between the tests (between subjects).
What we wish
2017 Sep 13
3
vcov and survival
Dear Terry,
Even the behaviour of lm() and glm() isn't entirely consistent. In both cases, singularity results in NA coefficients by default, and these are reported in the model summary and coefficient vector, but not in the coefficient covariance matrix:
----------------
> mod.lm <- lm(Employed ~ GNP + Population + I(GNP + Population),
+ data=longley)
>
2017 Nov 02
2
vcov and survival
>>>>> Fox, John <jfox at mcmaster.ca>
>>>>> on Thu, 14 Sep 2017 13:46:44 +0000 writes:
> Dear Martin, I made three points which likely got lost
> because of the way I presented them:
> (1) Singularity is an unusual situation and should be made
> more prominent. It typically reflects a problem with the
> data or the
2017 Sep 14
6
vcov and survival
>>>>> Martin Maechler <maechler at stat.math.ethz.ch>
>>>>> on Thu, 14 Sep 2017 10:13:02 +0200 writes:
>>>>> Fox, John <jfox at mcmaster.ca>
>>>>> on Wed, 13 Sep 2017 22:45:07 +0000 writes:
>> Dear Terry,
>> Even the behaviour of lm() and glm() isn't entirely consistent. In both cases,
2011 Dec 21
1
matrix multivariate bootstrap: order of results in $t component
[This question is hopefully straight-forward, but difficult to provide
reproducible code.]
I'm doing a multivariate bootstrap, using boot::boot(),
where the output of the basic computation is a k x p matrix of coefficients,
representing a tuning constant x variable, as shown in the $t0 component
from my run, giving a 3 x 6 matrix
> lboot$t0
GNP Unemployed Armed.Forces
2011 Aug 06
0
ridge regression - covariance matrices of ridge coefficients
For an application of ridge regression, I need to get the covariance
matrices of the estimated regression
coefficients in addition to the coefficients for all values of the ridge
contstant, lambda.
I've studied the code in MASS:::lm.ridge, but don't see how to do this
because the code is vectorized using
one svd calculation. The relevant lines from lm.ridge, using X, Y are:
2017 Sep 14
0
vcov and survival
>>>>> Fox, John <jfox at mcmaster.ca>
>>>>> on Wed, 13 Sep 2017 22:45:07 +0000 writes:
> Dear Terry,
> Even the behaviour of lm() and glm() isn't entirely consistent. In both cases, singularity results in NA coefficients by default, and these are reported in the model summary and coefficient vector, but not in the coefficient covariance
2017 Sep 14
0
vcov and survival
Dear Martin,
I made three points which likely got lost because of the way I presented them:
(1) Singularity is an unusual situation and should be made more prominent. It typically reflects a problem with the data or the specification of the model. That's not to say that it *never* makes sense to allow singular fits (as in the situations you mentions).
I'd favour setting
2001 Aug 23
2
multiple correlation?
I'm looking for a function for the 'multiple correlation' but can not figure
out what it is called in R by using the html search function. Maybe it is
called in another way in english? I only know the german term?
Can anyone help me?
Thomas Pesl
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read
2017 Sep 14
0
vcov and survival
Dear Terry,
It's not surprising that different modeling functions behave differently in this respect because there's no articulated standard.
Please see my response to Martin for my take on the singular.ok argument. For a highly sophisticated user like you, singular.ok=TRUE isn't problematic -- you're not going to fail to notice an NA in the coefficient vector -- but I've
2006 Jul 19
1
Test for equality of coefficients in multivariate multipleregression
Dear Berwin,
Simply stacking the problems and treating the resulting observations as
independent will give you the correct coefficients, but incorrect
coefficient variances and artificially zero covariances.
The approach that I suggested originally -- testing a linear hypothesis
using the coefficient estimates and covariances from the multivariate linear
model -- seems simple enough. For
2008 Oct 07
0
splinefun gives incorrect derivs when extrapolating to the (PR#13139)
--MP_/kvy20nVajVG/n.8m=_ZjLAX
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
On Tue, 7 Oct 2008 19:31:03 +0800
Berwin A Turlach <berwin at maths.uwa.edu.au> wrote:
> The attached patch (against the current SVN version of R) implements
> the latter strategy. With this patch applied, "make check
> FORCE=FORCE" passes
2016 Jan 12
0
On 'R CMD INSTALL' with multiple architectures
G'day all,
I guess it is still early enough in the year to wish everybody a happy
and successful new year.
I thought I should report that the installation of the CRAN package
rstan regularly fails on my machine (a 64 bit linux box running Xubuntu
15.10). The reason being that I have the 32-bit and the 64-bit
architecture of R installed, and my /tmp file is on a partition with
about 1Gb
2008 Feb 09
2
Reading data from a dataframe
Thanks for the replies to my prior question. My problem is that R always
says object not found when I enter a variable name into a command. I
converted a Stata file into an Rdata file by first loading the foreign
package by entering
require(foreign)
Then I asked R to read the Stata file by entering
pol572a1<- read.dta("C:\\alex\\Graduate Coursework\\Pol 572\\pol572a1.dta")
So
1997 Oct 21
1
R-beta: More Time series in the same plot
I can plot a time series with:
gnp <- ts(cumsum(1+round(rnorm(100), 2)), start=c(1954,7), frequency=12)
plot(gnp)
But I want to plot more time series in the same plot.
How can I do it?
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2003 Nov 04
1
hclust doesn't return merge details [Solved]
Thanks to Andy and Thomas,
Reading help(hclust) more carefully would have done it but sometimes you do not
see the wood for the trees...
So hc$merge does exactly what I want.
I have never been aware of the command str to get the structure of an R-object. It
seems pretty useful to me.
Thanks,
Arne
> -----Original Message-----
> From: Liaw, Andy [mailto:andy_liaw at merck.com]
>