Displaying 20 results from an estimated 1200 matches similar to: "how to use condition indexes to test multi-collinearity"
2003 Jul 23
6
Condition indexes and variance inflation factors
Has anyone programmed condition indexes in R?
I know that there is a function for variance inflation factors
available in the car package; however, Belsley (1991) Conditioning
Diagnostics (Wiley) notes that there are several weaknesses of VIFs:
e.g. 1) High VIFs are sufficient but not necessary conditions for
collinearity 2) VIFs don't diagnose the number of collinearities and 3)
No one has
2005 Mar 31
0
perturb package for evaluating collinearity
I've uploaded the R package "perturb" to CRAN. Perturb contains two
programs for evaluating collinearity. "Colldiag" calculates condition
indexes and variance decomposition proportions to detect and track
down collinear sets of variables.
"Perturb" takes a different approach. It re-estimates the model a
specified number of times, adding random noise
2005 Mar 31
0
perturb package for evaluating collinearity
I've uploaded the R package "perturb" to CRAN. Perturb contains two
programs for evaluating collinearity. "Colldiag" calculates condition
indexes and variance decomposition proportions to detect and track
down collinear sets of variables.
"Perturb" takes a different approach. It re-estimates the model a
specified number of times, adding random noise
2009 Jul 21
2
Collinearity in Linear Multiple Regression
Dear all,
How can I test for collinearity in the predictor data set
for multiple linear regression.
Thanks
Alex
[[alternative HTML version deleted]]
2005 Apr 21
0
colldiag
Hello,
could anyone explain what am I doing wrong. When I use colldiag function from package perturb I get different Variance Decomposition Proportions matrix in R than in SAS, although the eigenvalues and indexes are the same.
Thanks for your attention.
Results:
in R:
eigen(cor(indep2))
$values
[1] 4.197131e+00 6.674837e-01 9.462858e-02 4.070314e-02 5.323022e-05
colldiag(indep2,c=T)
2013 Feb 06
1
how to extract test for collinearity and constantcy used in lda
Hi everyone,
I'm trying to vectorize an application of lda to each 2D slice of a 3D
array, but am running into trouble: It seems there are quite a few 2D
slices that trigger either the "variables are collinear" warning, or worse,
trigger a "variable appears to be constant within groups" error and fails
(i.e., ceases computation rather than skips bad slice).
There are
2002 Jul 15
2
meaning of error message about collinearity
You are using a method that needs to estimate the covariance matrix of all
the variables. If you have 80 variables, there are (80+1)*80/2 = 3240
variances and covariances to estimate. How many data points do you think
you need to do that?
Some people assume the covariance matrix is diagonal (i.e., assuming all the
variables are uncorrelated). Even then you still have 80 variances to
estimate.
2008 Nov 20
1
Checking collinearity using lmer
I am running a logistic regression model with a random effect using lmer. I am uncertain how to check for collinearity between my parameters. I have already run cor() and linear regression for each combination of parameters, and all Rsqr values were <0.8….but I am analyzing ecological data so a 0.8 cutoff may be unrealistic.
-is there a way to check variance inflation factors or tolerance
2005 Jun 30
2
Finding out collinearity in regression
Hi, I am trying to find out a collinearity in
explanatory variables with alias().
I creat a dataframe:
dat <- ds[,sapply(ds,nlevels)>=2]
dat$Y <- Response
Explanatory variables are factor and response is
continuous random variable. When I run a regression, I
have the following error:
fit <- aov( Y ~ . , data = dat)
Error in "contrasts<-"(`*tmp*`, value =
2004 Aug 16
2
mutlicollinearity and MM-regression
Dear R users,
Usually the variance-inflation factor, which is based on R^2, is used as a
measure for multicollinearity. But, in contrast to OLS regression there is
no robust R^2 available for MM-regressions in R. Do you know if an
equivalent or an alternative nmeasure of multicollinearity is available for
MM-regression in R?
With best regards,
Carsten Colombier
Dr. Carsten Colombier
Economist
2004 Jun 11
4
Regression query
Hi
I have a set of data with both quantitative and categorical predictors.
After scaling of response variable, i looked for multicollinearity (VIF
values)
among the predictors and removed the predictors who were hinding some of the
other significant
predictors. I'm curious to know whether the predictors (who are not
significant)
while doing simple 'lm' will be involved in
2006 Jul 05
2
Colinearity Function in R
Is there a colinearty function implemented in R? I
have tried help.search("colinearity") and
help.search("collinearity") and have searched for
"colinearity" and "collinearity" on
http://www.rpad.org/Rpad/Rpad-refcard.pdf but with no
success.
Many thanks in advance,
Peter Lauren.
2003 Jun 30
1
Novice Questions
I'm writing a program to perform linear regressions to
estimate the number of bank teller transactions per
hour of various types based upon day of week, time of
day, week of month and several prices. I've got about
25,000 records in my dataset, 85 columns of
transaction counts (used 1 at a time), about 50
columns of binary indicators (day, week, pay period,
hour, branch), and a half dozen
2003 Jun 05
2
ridge regression
Hello R-user
I want to compute a multiple regression but I would to include a check for
collinearity of the variables. Therefore I would like to use a ridge
regression.
I tried lm.ridge() but I don't know yet how to get p-values (single Pr() and p
of the whole model) out of this model. Can anybody tell me how to get a
similar output like the summary(lm(...)) output? Or if there is
2012 Jun 01
4
regsubsets (Leaps)
Hi
i need to create a model from 250 + variables with high collinearity, and
only 17 data points (p = 250, n = 750). I would prefer to use Cp, AIC,
and/or BIC to narrow down the number of variables, and then use VIF to
choose a model without collinearity (if possible). I realize that having a
huge p and small n is going to give me extreme linear dependency problems,
but I *think* these model
2003 Sep 16
2
gam and concurvity
Hello,
in the paper "Avoiding the effects of concurvity in GAM's .." of Figueiras et
al. (2003) it is mentioned that in GLM collinearity is taken into account in
the calc of se but not in GAM (-> results in confidence interval too narrow,
p-value understated, GAM S-Plus version). I haven't found any references to
GAM and concurvity or collinearity on the R page. And I
2005 Apr 11
2
dealing with multicollinearity
I have a linear model y~x1+x2 of some data where the
coefficient for
x1 is higher than I would have expected from theory
(0.7 vs 0.88)
I wondered whether this would be an artifact due to x1
and x2 being correlated despite that the variance
inflation factor is not too high (1.065):
I used perturbation analysis to evaluate collinearity
library(perturb)
2010 Aug 03
2
Collinearity in Moderated Multiple Regression
Dear all,
I have one dependent variable y and two independent variables x1 and x2
which I would like to use to explain y. x1 and x2 are design factors in an
experiment and are not correlated with each other. For example assume that:
x1 <- rbind(1,1,1,2,2,2,3,3,3)
x2 <- rbind(1,2,3,1,2,3,1,2,3)
cor(x1,x2)
The problem is that I do not only want to analyze the effect of x1 and x2 on
y but
2010 Aug 29
2
glm prb (Error in `contrasts<-`(`*tmp*`, value = "contr.treatment") : )
glm(A~B+C+D+E+F,family = binomial(link = "logit"),data=tre,na.action=na.omit)
Error in `contrasts<-`(`*tmp*`, value = "contr.treatment") :
contrasts can be applied only to factors with 2 or more levels
however,
glm(A~B+C+D+E,family = binomial(link = "logit"),data=tre,na.action=na.omit)
runs fine
glm(A~B+C+D+F,family = binomial(link =
2017 May 04
4
lm() gives different results to lm.ridge() and SPSS
Hallo,
I hope I am posting to the right place. I was advised to try this list by Ben Bolker (https://twitter.com/bolkerb/status/859909918446497795). I also posted this question to StackOverflow (http://stackoverflow.com/questions/43771269/lm-gives-different-results-from-lm-ridgelambda-0). I am a relative newcomer to R, but I wrote my first program in 1975 and have been paid to program in about