Displaying 20 results from an estimated 2000 matches similar to: "Contrasts for ordered factors"
2009 Dec 17
1
poly() with unnormalized values
How can I get the result of, e.g., poly(1:3. degree=2) to give me the
unnormalized integer coefficients
usually used to explain orthogonal polynomial contrasts, e.g,
-1 1
0 -2
1 1
As I understand things, the columns of x^{1:degree} are first centered
and then
are normalized by 1/sqrt(col sum of squares), but I can't
see how to relate this to what is returned by poly().
>
2008 Mar 07
5
Puzzling coefficients for linear fitting to polynom
Hi,
I can not comprehend the linear fitting results of polynoms. For
example, given the following data (representing y = x^2):
> x <- 1:3
> y <- c(1, 4, 9)
performing a linear fit
> f <- lm(y ~ poly(x, 2))
gives weird coefficients:
> coefficients(f)
(Intercept) poly(x, 2)1 poly(x, 2)2
4.6666667 5.6568542 0.8164966
However the fitted() result makes sense:
>
2005 Feb 23
1
model.matrix for a factor effect with no intercept
I was surprised by this (in R 2.0.1):
> a <- ordered(-1:1)
> a
[1] -1 0 1
Levels: -1 < 0 < 1
> model.matrix(~ a)
(Intercept) a.L a.Q
1 1 -7.071068e-01 0.4082483
2 1 -9.073800e-17 -0.8164966
3 1 7.071068e-01 0.4082483
attr(,"assign")
[1] 0 1 1
attr(,"contrasts")
attr(,"contrasts")$a
[1]
1999 May 04
1
surrogate poisson models
Dear R-help,
I'm applying the surrogate Poisson glm, by following Venables & Ripley (7.3
pp238-42).
>overall_cbind(expand.grid(treatment=c("Pema","control"),age=c("young","adult","old"),repair=c("excellent","good","poor")),Fr=c(8,0,7,1,2,0,2,7,1,4,7,1,
0,3,2,5,1,9))
2018 Feb 16
2
[FORGED] Re: SE for all levels (including reference) of a factor atfer a GLM
On 16/02/18 15:28, Bert Gunter wrote:
> This is really a statistical issue. What do you think the Intercept term
> represents? See ?contrasts.
>
> Cheers,
> Bert
>
>
>
> Bert Gunter
>
> "The trouble with having an open mind is that people keep coming along and
> sticking things into it."
> -- Opus (aka Berkeley Breathed in his "Bloom
2018 Feb 16
0
SE for all levels (including reference) of a factor atfer a GLM
This is really a statistical issue. What do you think the Intercept term
represents? See ?contrasts.
Cheers,
Bert
Bert Gunter
"The trouble with having an open mind is that people keep coming along and
sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
On Thu, Feb 15, 2018 at 5:27 PM, Marc Girondot via R-help <
r-help at
2014 Aug 08
6
[LLVMdev] Plan to optimize atomics in LLVM
> I am planning in doing in IR, but with target specific-passes (such as X86ExpandAtomicPass)
> that just share some of the code
This would more normally be done via target hooks in LLVM, though the
principle is sound.
> But it must be target-dependent as for example on Power a
> seq_cst store has a fence before it, while on ARM it has a fence
> both before and after it (per
2018 Feb 16
2
SE for all levels (including reference) of a factor atfer a GLM
Dear R-er,
I try to get the standard error of fitted parameters for factors with a
glm, even the reference one:
a <- runif(100)
b <- sample(x=c("0", "1", "2"), size=100, replace = TRUE)
df <- data.frame(A=a, B=b, stringsAsFactors = FALSE)
g <- glm(a ~ b, data=df)
summary(g)$coefficients
# I don't get SE for the reference factor, here 0:
2004 Jan 08
3
Strange parametrization in polr
In Venables \& Ripley 3rd edition (p. 231) the proportional odds model
is described as:
logit(p<=k) = zeta_k + eta
but polr apparently thinks there is a minus in front of eta,
as is apprent below.
Is this a bug og a feature I have overlooked?
Here is the naked code for reproduction, below the results.
------------------------------------------------------------------------
---
version
1999 Jun 30
1
qr and Moore-Penrose
> Date: Wed, 30 Jun 1999 11:12:24 +0200 (MET DST)
> From: Torsten Hothorn <hothorn at amadeus.statistik.uni-dortmund.de>
>
> yesterday I had a little shock using qr (or lm). having a matrix
>
> X <- cbind(1,diag(3))
> y <- 1:3
>
> the qr.coef returns one NA (because X is singular). So I computed the
> Moore-Penrose inverse of X (just from the
2015 Oct 25
2
Differences between qemu-kvm and qemu-kvm-ev
Hi all,
What are the real technical difference between qemu-kvm and
qemu-kvm-ev packages? What are the advantages to use qemu-kvm-ev (if
exists someone)?
Or qemu-kvm-ev makes sense when is used with ovirt only??
Thanks.
2010 Aug 21
1
Speed improvement to evalList
I've been inspired to look at the R source code by some strange timing
results that I wrote about on my blog at radfordneal.wordpress.com
(see the posts on "Speeding up parentheses..." and "Two surprising
things...".
I discovered that the strange speed advantage of curly brackets over
parentheses is partially explained by an inefficiency in the evalList
and
2005 Jan 31
4
aggregating dates
I have a frame which contains 3 columns:
"date" "defectnum" "state"
And I want to get the most recent state change for a given defect number. date is POSIXct.
I have tried:
aggregate(ev$date, by=list(ev$defectnum), max)
Which appears to be working except that the dates seem to come back as integers (presumably the internal representation of POSIXct).
When I
2018 May 10
3
Difference between qemu-kvm-ev and qemu-kvm-ma?
I see with the introduction of CentOS 7.5 there's a new qemu-kvm-ma package
on ppc64le (which is actually newer than qemu-kvm-ev currently). Does
anyone know what the difference is between these two packages? We currently
use qemu-kvm-ev and we've run into this bug [1] which got me wondering if
we should be switching to that package on ppc64le.
Thanks!
[1]
2020 May 11
3
kvm: C8 as guest on C6 host / huge delay while booting
Since C8.1 kvm guests have a huge delay while booting on a kvm host
based on C6. This delay was not present with C8.0. The "pause" happend
direct after the grub step. The VNC session shows only a "_" character.
Any ideas what changes?
--
Leon
2006 Aug 02
1
read.spss and umlaut
Hello
When I read a SPSS *.por file with read.spss everything after a umlaut is
missing:
> library("foreign")
> spssdaten <- read.spss("projets.por")
> attr(spssdaten$PROJETX, "value.labels")[1:20]
Bg Stammzellenforschung Bb
863 862
Bb
2018 May 15
2
centos-qemu-ev repository not work for x86_64 arch on CentOS 7.5
Hello, Sandro!
On 11.05.2018 12:19, Sandro Bonazzola wrote:
> Sadly, the new qemu-kvm-ev we prepared for CentOS 7.5 didn't get released (
> https://bugs.centos.org/view.php?id=14764) but the new build is ready.
After installing CentOS 7.5 and installing package qemu-kvm-ev
I can't install KVM on x86_64 arch:
command "yum -y install perf qemu-kvm-ev qemu-kvm-tools-ev
2013 Aug 12
2
Odd Samba 4 ("4.2.0pre1-GIT-b505111"; actually only using client) behaviour #2 - "accept: Software caused connection abort".
Good day oh technical ones .
I was running Samba 4 (client only, not using it as a DC so
effectively running Samba 3 code from the Samba 4 tree) and, other than a
little "Gotcha!" regarding decoding Kerberos PACs, it was all working
perfectly.
Then recently I had to upgrade, to "4.2.0pre1-GIT-b505111"
(I had to upgrade the OS on the server
2007 Oct 01
1
[nls] singular gradient
Hi, I am new to R. I don't have strong background of statistics. I am
a student of Geotechnical Engineering. I tried to run a nonlinear
regression for a three-variable function, that is
N = f(CSR, ev) # N is a function of CSR and ev, and N = CSR/(A
+B*CSR), wherer (A,B) are function of ev.
N, CSR and ev are observed in the experiments.
Following is my R script.
rm(list=ls())
2017 Jul 26
2
qemu-system-x86_64 does not support fw_cfg option
Hi
I am trying to run CoreOS (Container Linux) as a guest OS using
KVM/QEMU. One of their suggestions is to pass config info into the VM
using the "fw_cfg" option . When I try this I get the error "-fw_cfg
invalid option". If I run the vm with the help option it does not list
the fw_cfg option. However, according to the qemu documentation, see
here