search for: confounded

I am working on my thesis in which i have couple of independent variables that are categorical in nature and the depndent variable is dichotomus. Initially I run univariate analysis and added the variables with significant p-values (p<0.25) in my full model. I have three confusions. Firstly, I am looking for confounding variables by using formula "(crude beta-cofficient - adjusted

Hi, I am doing a retrospective analysis on a cohort from a designed trial, and I am fitting the model fit<-glmD(survived ~ Covariate*Therapy + confounder,myDat,X=TRUE, Y=TRUE, family=binomial()) My covariate has three levels ("A","B" and "C") and therapy has two (treated and control), confounder is a continuous variable. Also patients were randomized to

...#39;**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 Residual standard error: 0.971 on 6 degrees of freedom Multiple R-Squared: 0.5086, Adjusted R-squared: 0.2629 F-statistic: 2.07 on 3 and 6 DF, p-value: 0.2057 In this case, I can look at data and figure out which variable is confounded with which. But, if we have many categorial covariates ( not necessarily same number of levels ), it is almost impossible to check it out. Any help would be greatly appreicated. Thanks. Young.

Dear all I am struggling with how to deal with missing values using geeglm. I know that geeglm only works with complete datasets, but I cannot seem to get the na.omit function to work. For example assuming DataMiss contains 3 columns, each of which has missing observations, and an id column with no missing info then identifies the clusters. Outcome: 2 level integer Predictor: numeric variable

The following R commands were written: >help.search("factorial") >data(npk) >npk >coef(npk.aov) In the output of coef command, please explain me the interpretation of coefficients of block1 to block 6 in this 2^3 confounded factorial experiment. Thanks. [[alternative HTML version deleted]]

...nablerepo=base clean metadata? I?ve done that. I?ve done ?yum clean all?. I?ve done ?yum clean all && rm -rf /var/cacheyum? I?ve blown away the 7.5.1804 tree in my mirror and resync?d it and it still does it. If I change the 7 -> 7.5.1804 symlink to 7.4, yum update runs fine. I?m confounded. How can I check the repo data files on my copy against the tree to see where or if it?s blowing up. Oddly, if I point the host I?m updating at the SAME server I?m mirroring from and do a yum update, it works fine. Using rsync to update. Out of Ideas, EKG

I am trying to use the CART in a survival analysis. I have three variables of interest (all 3 ordinal - x, y and z, each of them with 5 categories) from which I want to make smaller groups (just an example 1st category from X variable with the 2nd and 3rd categories from the Y category and 2, 3 and 4 categories from the Z category etc) based on their, let's say, association with mortality. Now

This is probably a know problem (problem for me anyway) in R but I don't quite know what to search for in help archives. When I name a column "x11" in a data frame R thinks a column named "x1" exists. In my application I am trying to test for the existence of a column, then add it if it's not there. Here is a simple example: > temd <- data.frame(x11=c(0:10)) >

Hello, I am trying to find an R function to compute 'direct adjusted survival' with standard errors. A SAS-macro to do this is presented in Zhang X, Loberiza FR, Klein JP, Zhang MJ. A SAS macro for estimation of direct adjusted survival curves based on a stratified Cox regression model. Comput Methods Programs Biomed 2007;88:95-101. It appears that this method is not implemented in R.

I don't know if this is the best place to post this question but I will try anyway. I have two experiements for which I use one-way matched-randomized ANOVA for the analysis and I would like to compare different treatments in the two experiments. The only common group in the two experiments are the controls. Is there any ANOVA design that allows me to make this comparison taking into

Hi all, Does anybody know if it is possible to build a fractional factorial design in R? That is, suppose that we want do design an experiment with 3 factors with 2, 3 and 3 levels, respectivly. However we want to consider, let's say, only 6 from all possible level combinations. Does R design such experiment? Thanks in advance, Caio [[alternative HTML version deleted]]

Windows Vista R 2.10 - I know it is old, I will update later today. How might I perform a piece-wise linear regression where two linear segments are separated by a single knot? In addition to estimating the slopes of the two segments (or the slope in one segment and the difference between the slope of the first and second segment), I would like the analysis to select the optimum knot. My first

oops, Forgot to cc to the list. Regards, Mike -----Original Message----- From: dr mike [mailto:dr.mike at ntlworld.com] Sent: 24 February 2005 19:21 To: 'Spencer Graves' Subject: RE: [R] Bayesian stepwise (was: Forward Stepwise regression based onpartial F test) Spencer, Obviously the problem is one of supersaturation. In view of that, are you aware of the following? A Two-Stage

Dear All, My question is more a statistical question than a R question. The reason I am posting here is that there are lots of excellent statistician on this list, who can always give me good advices. Per my understanding, the purpose of propensity score is to reduce the bias while estimating the treatment effect and its implementation is a 2-stage model. 1) First of all, if we assume that T =

Hello, This is a problem for which there seem to be several solutions online, but not really. My question was about plotting a curve over the histogram. All the previous posts and messages talk about generating a *density histogram*using (freq=F) and then plotting the density curve. However, I find that that seriously distorts my data and the plot becomes confounding to the viewer. I was

Hi everyone, I have a question that seems simple, but has been confounding me for several hours. I'd like to debug a binary produced with LLVM. For the life of me, I can't get any symbols into gdb and llvm-db won't even start the program nor load any useful information about it. Here's my current strategy (which isn't working): llvm-gcc -g -O0 -c -emit-llvm

...uot;special") plot(x, dnorm(x), type="l") dev.off() By LaTeX PDF, I am referring to the dvips->ghostscript pathway, but x2.eps also rotates when distilled into PDF outside LaTeX. I have tried ghostscript and acrobat, placed on a page or cropped, so the problem does not seem to be confounded with particular PDF distillation software. I'm aware of the pdf() device in R, but EPS files are a widely used format to share scientific graphics, often winding up embedded in a PDF document at a later point in the hands of an editor. If at all possible, a more predictable postscript generat...

Dear List, I've just tried to specify a GAM without an intercept -- I've got one of the (rare) cases where it is appropriate for E(y) -> 0 as X ->0. Naively running a GAM with the "-1" appended to the formula and the calling "predict.gam", I see that the model isn't behaving as expected. I don't understand why this would be. Google turns up this old

...estimate the main effects. The factors may have any number of levels, let's say any number from 2 to 6. I've tried to use the library conf.design , but i cannot figure out how to write the code. For example, what is the code for a design with 5 factors (2x3x3x5x2) and only main effects not confounded? thanks in advance! Roberto Furlan University of Turin, Italy PS: i've already tried to send this email, sorry if you 've received it again! ---------------------------------------- La mia Cartella di Posta in Arrivo ?? protetta con SPAMfighter 188 messaggi contenenti spam sono stati blo...

Hi strange behaviour of iptables on a centos 7.0 machine: The following rule is in the iptables of said machine: [root at myserver ~]# iptables -L -v -n --line-numbers |grep 175\. 9 9 456 DROP all -- * * 175.44.0.0/16 0.0.0.0/0 [root at myserver ~]# The corresponding enty in /etc/sysconfig/iptables looks like: [root at myserver ~]# grep 175 /etc/sysconfig/iptables