Displaying 20 results from an estimated 70 matches similar to: "why does R stepAIC keep unsignificant variables?"
2012 Oct 03
2
Error in if (any(ch)) { : missing value where TRUE/FALSE needed
Can someone please help with the error message below?
thanks!
Start: AIC=-Inf
value ~ 1 + Core_CPI__ + GDP_change + Unemployment + housing +
interest + S_P + d1 + d2 + d3
Error in if (any(ch)) { : missing value where TRUE/FALSE needed
In addition: Warning message:
attempting model selection on an essentially perfect fit is nonsense
2012 Jul 12
1
Cox proportional hazard model and coefficients
Hi,
Here is the summary-output of the Coxph-model I used (the output is based on
the best final model i.e. all significant explanatory variables and their
interactions are included):
coxph(formula = Y ~ LT + Food + Temp2 + LT:Food + LT:Temp2 +
Food:Temp2 + LT:Food:Temp2)
n= 555
coef exp(coef)
se(coef) z
2003 Jul 14
1
gam and step
hello,
I am looking for a step() function for GAM's.
In the book Statistical Computing by Crawley and a removal of predictors has
been done "by hand"
model <- gam(y ~s(x1) +s(x2) + s(x3))
summary(model)
model2 <- gam(y ~s(x2) + s(x3)) # removal of the unsignificant variable
#then comparing these two models if an significant increase occurs.
anova(model, model2,
2006 Apr 25
1
lme: how to compare random effects in two subsets of data
Dear R-gurus,
I have an interpretation problem regarding lme models.
I am currently working on dog locomotion, particularly on some variation
factors.
I try to figure out which limb out of 2 generated more dispersed data.
I record a value called Peak, around 20 times for each limb with a record.
I repeat the records during a single day, and on several days.
I tried to build two models, one
2008 Nov 07
0
clogit and small sample sizes: what to do?
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Conditional logistic regression and small sample sizes: what to do?
Dear R-Gurus,
[I run R 2.8.0 on WinXP. I have no formal training in statistics.]
Please feel free to skip the 'Blah blah part' for questions below.
- ---Blah blah part--------
Why I use clogit (package 'survival')?: I am looking for risk factors
for cases during a
2005 Mar 15
0
Fwd: RODBC, sqlSave and sqlAppend
Début du message réexpédié :
> De: Depiereux Constant <constant.depiereux@aqte.be>
> Date: 16 mars 2005 00:11:11 GMT+01:00
> À: spjgmwn@iop.kcl.ac.uk
> Objet: Rép : [R] RODBC, sqlSave and sqlAppend
>
>
> Le 15-mars-05, à 16:19, Matthew W Nash a écrit :
>
>> Hi all,
>>
>> I am currently trying to read, write and append data between R and MS
2009 Jun 07
0
Speex quality estimation in lossless media
Hi,
There is a lot of speex quality estimations. One of this comparative
estimation is even available on the official site
<http://speex.org/comparison/>.
I'd like to present yet another one. And I thought that the best place
for this presentation would be Speex-dev mailing list. I want to get
feedbacks and criticisms please. If Speex authors consider to make
some parts of this work
2012 Mar 14
2
Maximization problem in the optim function
Dear R Users
I am maximizing a user defined log likelihood function. It includes variance
parameter (sigma). I used R function optim with BFGS maximization method.
However, it stops before the solution saying ?sqrt(sigma): NaNs produced?
Could anybody know a proper transformation for sigma which can be passed in
the function? For the correlation parameter I used Fishers? transformation
so it
2011 Jan 26
2
write.table -- maintain decimal places
Hello, All,
How can I maintain the decimal places when using write.table()?
Jim
e.g.
df:
EFFECT2 PVALUE
1 0.023 0.88080
2 -0.260 0.08641
3 -0.114 0.45200
write.table(df,file='df.txt',quote=F,sep='\t',row.names=F)
df.txt:
EFFECT2 PVALUE
0.023 0.8808
-0.26 0.08641
-0.114 0.452
[[alternative HTML version deleted]]
2004 Jul 11
2
Interpreting Results of Bootstrapping
I tried to bootstrap the correlation between two
variables x1 and x2. The resulting distribution has
two distinct peaks, how should I interprete it?
The original code is attached.
Y. C. Tao
----------------
library(boot);
my.correl<-function(d, i) cor(d[i,1], d[i,2])
x1<-c(-2.612,-0.7859,-0.5229,-1.246,1.647,1.647,0.1811,-0.07097,0.8711,0.4323,0.1721,2.143,
2002 Apr 19
1
FW: Problem compiling on HP-UX 10.20
Here is a copy of the last few lines in base-Ex.Rout.fail:
> x <- seq(3,500);yl <- c(-.3, .2)
> plot(x,x, ylim = yl, ylab="",type='n', main = "Bessel Functions
Y_nu(x)")
> for(nu in nus){xx <- x[x > .6*nu]; lines(xx,besselY(xx,nu=nu), col =
nu+2)}
> legend(300,-.08, leg=paste("nu=",nus), col = nus+2, lwd=1)
>
> x <-
2010 Dec 01
1
Poisson GLM warning message
Hi,
I receive the following warning message when I run a poisson GLM in R:
"glm.fit: fitted rates numerically 0 occurred"
The model summary is shown below. The variable 'Species' consists of
counts of different species ranging from 0 to 4. I suspect this may
have something to do with the warning message but I'm not sure. Can
anybody help?
Thank you!
Anna
Call:
2007 Feb 06
1
ANOVA Table for Full Linear Model?
Hello,
I have spent a good deal of time searching for an answer to this but
have come up empty-handed; I apologize if I missed something that is
common knowledge.
I am trying to figure out how to get an ANOVA table that shows the
sum of squares. degrees of freedom, etc, for the full model versus
the error (aka residuals).
Here is an example of the kind of table I'd like to get:
2012 Mar 28
2
Data extraction
Dear ReXperts,
I have the below text file output. I need to extract the T, QC, QO, QO-QC
and WT columns for
the data between T = 10 and T=150.
Any ideas?
Thanks in advance.
========================================================================================
1 D C ---CAT-- T THETA QC QO
QO-QC QC/QO WT FSD
8 1 0 1.0000E+01
2007 Dec 09
2
Large determinant problem
I thought I would have another try at explaining my problem. I think that
last time I may have buried it in irrelevant detail.
This output should explain my dilemma:
> dim(S)
[1] 1455 269
> summary(as.vector(S))
Min. 1st Qu. Median Mean 3rd Qu. Max.
-1.160e+04 0.000e+00 0.000e+00 -4.132e-08 0.000e+00 8.636e+03
> sum(as.vector(S)==0)/(1455*269)
[1]
2005 Dec 13
2
what does this warnings mean? and what should I do?
I use lmer to fit a mixed effect model.It give some warnings.what does this warnings mean? and what should I do?
> (fm2.mlm <- lmer(qd ~ edu + jiankang + peixun +hunyin + cadcj + age + age2 + sex + dangyuan + Comp.1 + Comp.2+trust.cz1 +(trust.cz1|commid), data = individual,na.action = "na.exclude",family="quasibinomial"))
Generalized linear mixed model fit using PQL
2006 Mar 08
1
power and sample size for a GLM with Poisson response variable
Craig, Thanks for your follow-up note on using the asypow package. My
problem was not only constructing the "constraints" vector but, for my
particular situation (Poisson regression, two groups, sample sizes of
(1081,3180), I get very different results using asypow package compared
to my other (home grown) approaches.
library(asypow)
pois.mean<-c(0.0065,0.0003)
info.pois <-
2007 Oct 05
0
discrepancy in the result of R and SAS on same data in logistics regression
Dear Members,
Greetings!
I have come across a discrepancy shown by R and SAS results on same data for logistics regression..
When I processed the above csv file(1000.csv) for predicting the Action (i/c) by Age Group(1-7,Na) and Gender(M,F,Na) with GLM of R I get:
R result
Call:
glm(formula = Action ~ Gender + AgeGroup, family = binomial,
data = mydata1, na.action = na.pass)
Deviance
2005 Jul 29
0
PLS component selection for GPLS question
How to select the number of PLS components for GPLS for data sets
with few samples?
Concrete problem:
My data set: 9 samples of class A and 37 of class B with 254
descriptors.
In the paper: "Classification Using Generalized Partial Least
Squares", Beiying Ding, Robert Gentleman, Bioconductor
Project Working Papers, year 2004, paper 5
Section 2.6 Assessing Prediction:
Cite:
2006 May 17
3
WebServices: execution expired
1 hour spent and I can''t got explanation why I have "execution expired"
when I trying to test this web service:
Pointed to: http://localhost:3000/news/list
class NewsService < ActionWebService::Base
web_service_api NewsApi
def list
[NewsTopic.new, NewsTopic.new]
end
end
class NewsController < ApplicationController
wsdl_service_name ''news''