Displaying 20 results from an estimated 5000 matches similar to: "plot(aModel) vs. influence.measures()"
2010 Feb 21
1
tests for measures of influence in regression
influence.measures gives several measures of influence for each
observation (Cook's Distance, etc) and actually flags observations
that it determines are influential by any of the measures. Looks
good! But how does it discriminate between the influential and non-
influential observations by each of the measures? Like does it do a
Bonferroni-corrected t on the residuals identified by
2010 Oct 07
6
Deleting observations - can't see the data after that
Hello all,
I am loading a data frame, fitting a model, getting diagnostic plots and they are flagging a couple of observations as problematic. Fair enough, and I want re-fit without them.
After I delete an offending row (identified by one of the diagnostic plots), something like
data = data[-3,];
then R will no longer print the contents of the data frame; it tells me it is a data frame
1999 Jun 23
1
Influence.measures
I am using rw0641 with Windows 98. To list just the influential
repetitiones that result from "influence.measures", I am using the input
result <- lm(y~x)
and the code from the example in the help for "influence.measures"
INFLM <- function(result){
inflm <- influence.measures(result)
which(apply(inflm$is.inf,1,any))
}
It works fine up to now with the
2010 Oct 13
7
[OT] (slightly) - OpenOffice Calc and text files
Hello all,
I had a very strange looking problem that turned out to be due to unexpected (by me at least) format changes to one of my data files. We have a small lab study in which each run is represented by a row in a tab-delimited file; each row identifies a repetition of the experiment and associates it with some subjective measurements and times from our notes that get used to index another
2012 Feb 15
1
influence.measures()
Hi dear all,
I'm wondering about the question that; Does the influence.measures(model)
for linear models valid for general linear models such as logistic
regression models?
That is;
If I fit the model like
model <- glm( y~X1+X2, family=binomial)
Then, if i apply the function "influence.measures(model), i will get the
result of influence measures.
These result are valid for
2008 Mar 09
1
Formula for whether hat value is influential?
I was wondering if someone might be able to tell me what formula R's
influence.measures function uses for determining whether the hat value
it computes is influential (i.e., the true/false value in the "hat"
column of the returned is.inf data frame). The reason I'm asking is
that its results disagree with what I've just learned in my statistics
class, namely that a point
2011 Jan 27
1
Minor typo in influence.measures.Rd ?
Dear list,
There is, I believe, a minor typo in the example section of
influence.measures.Rd. In the final example the word `does` appears
where I suspect `dose` is required:
I couldn't remember exactly what format patches should be in, so here is
one as diff would produce:
Index: devel/src/library/stats/man/influence.measures.Rd
2004 Mar 23
1
influence.measures, cooks.distance, and glm
Dear list,
I've noticed that influence.measures and cooks.distance gives different
results for non-gaussian GLMs. For example, using R-1.9.0 alpha
(2003-03-17) under Windows:
> ## Dobson (1990) Page 93: Randomized Controlled Trial :
> counts <- c(18,17,15,20,10,20,25,13,12)
> outcome <- gl(3,1,9)
> treatment <- gl(3,3)
> glm.D93 <- glm(counts ~ outcome +
2010 May 05
2
OLS Regression diagnostic measures check list - what to consider?
Hello dear R help list,
I wish to compile a check-list for diagnostic measures for OLS regression.
My question:
Can you offer more (or newer) tests/measures for the validity of a linear
model then what is given here:
http://www.statmethods.net/stats/rdiagnostics.html
This resource gives a list of measures to test for:
OUTLIERS, INFLUENTIAL OBSERVATIONS, NON-NORMALITY, NON-CONSTANT ERROR
2002 Jul 22
0
Influence Measures for .lme models
Many thanks to those who replied to my message regarding installation of the lattice package. I have now upgraded my version of R.
I have a quick question:
I am running mixed effects models using the lme command. I am wanting to assess the fit of these models
using the usual plots including Cooks Distance plots.
I have noticed from the help files that it is possible to run influence measures
2003 Jun 12
0
rigde regression and influence measures
I make a regression using the lm.rigde function from library MASS. Now i
want some measures of influence.
Is there a way to use a lm.ridge object into the function
influence.measures?
--
bertola at fastmail.fm
--
2010 Sep 14
0
influence measures for multivariate linear models
I'm following up on a question I posted 8/10/2010, but my newsreader
has lost this thread.
> Barrett & Ling, JASA, 1992, v.87(417), pp184-191 define general
> classes of influence measures for multivariate
> regression models, including analogs of Cook's D, Andrews & Pregibon
> COVRATIO, etc. As in univariate
> response models, these are based on leverage and
2010 Aug 10
1
influence measures for multivariate linear models
Barrett & Ling, JASA, 1992, v.87(417), pp184-191 define general classes
of influence measures for multivariate
regression models, including analogs of Cook's D, Andrews & Pregibon
COVRATIO, etc. As in univariate
response models, these are based on leverage and residuals based on
omitting one (or more) observations at
a time and refitting, although, in the univariate case, the
2010 Oct 15
0
nomianl response model
Is there a way to estimate a nominal response model?
To be more specific let's say I want to calibrate:
\pi_{v}(\theta_j)=\frac{e^{\xi_{v}+\lambda_{v}\theta_j}}{\sum_{h=1}^m
e^{\xi_{h}+\lambda_{h}\theta_j}}
Where $\theta_j$ is a the dependent variable and I need to estimate
$\xi_{h}$ and $\lambda_{h}$ for $h \in {1...,m}$.
Thank you,
Mauricio Romero
Quantil S.A.S.
Cel: 3112231150
2010 Aug 03
4
REmove level with zero observations
If I have a column with 2 levels, but one level has no remaining
observations. Can I remove the level?
Had intended to do it as listed below, but soon realized that even though
there are no observations, the level is still there.
For instance
summary(dbs3.train.sans.influential.obs$HAC)
yields
0 ,1
4685,0
nlevels(dbs3.train.sans.influential.obs$HAC)
yields
[1] 2
drop.list <- NULL
2004 Feb 10
1
make check in 1.8.1.
I just (finally!!!) got R version 1.8.1 to configure and build under
Solaris 9 (after much travail; there were funnies in my environment
variables that mucked things up, but that's another story).
Anyhow, when I ran ``make check'' I got an error right toward the
end. Looking in the directory ``tests'' I found that the error was
associated with the file reg-tests-3.R, and the
2006 Aug 31
1
NaN when using dffits, stemming from lm.influence call
Hi all
I'm getting a NaN returned on using dffits, as explained
below. To me, there seems no obvious (or non-obvious reason
for that matter) reason why a NaN appears.
Before I start digging further, can anyone see why dffits
might be failing? Is there a problem with the data?
Consider:
# Load data
dep <-
2009 Nov 08
2
influence.measures(stats): hatvalues(model, ...)
Hello:
I am trying to understand the method 'hatvalues(...)', which returns something similar to the diagonals of the plain vanilla hat matrix [X(X'X)^(-1)X'], but not quite.
A Fortran programmer I am not, but tracing through the code it looks like perhaps some sort of correction based on the notion of 'leave-one-out' variance is being applied.
Whatever the
2010 Feb 25
2
Ordering categories on a boxplot - a serious trap??
Hello all,
I think I probably did something stupid, and R's part was to allow me to do it. My goal was to control the order of factor levels appearing horizontally on a boxplot. Enter search engines and perhaps some creative stupidity on my part, and I came up with the following:
v=read.table("factor-order.txt",header=TRUE);
levels(v$doseGroup) = c("L", "M",
2016 Jul 27
3
[RFC] One or many git repositories?
On 7/27/2016 12:17 PM, Chris Bieneman wrote:
>
> This is a really bad argument for large influential changes like this.
Quite the contrary---anybody can participate and anybody can express
their concerns, explain their goals, their workflow, etc. For a large
influential changes like this, "zoning out" is a poor choice of action.
> I suspect this is why the idea of having a