similar to: Missing Data in Stepwise selection of Logistic regression

Displaying 20 results from an estimated 3000 matches similar to: "Missing Data in Stepwise selection of Logistic regression"

2005 Apr 13
1
logistic regression weights problem
Hi All, I have a problem with weighted logistic regression. I have a number of SNPs and a case/control scenario, but not all genotypes are as "guaranteed" as others, so I am using weights to downsample the importance of individuals whose genotype has been heavily "inferred". My data is quite big, but with a dummy example: > status <- c(1,1,1,0,0) > SNPs <-
2006 Apr 06
4
Reshaping genetic data from long to wide
Bottom Line Up Front: How does one reshape genetic data from long to wide? I currently have a lot of data. About 180 individuals (some probands/patients, some parents, rare siblings) and SNP data from 6000 loci on each. The standard formats seem to be something along the lines of Famid, pid, fatid, motid, affected, sex, locus1Allele1, locus1Allele2, locus2Allele1, locus2Allele2, etc In other
2011 Dec 10
3
Overlaying density plot on forest plot
Dear R User, Please, I am new to R. I want to overlay density plot for predictive interval pooled result in meta-analysis. http://addictedtor.free.fr/graphiques/graphcode.php?graph=114 Regards Frank Peter
2013 Oct 03
1
prcomp - surprising structure
Hello, I did a pca with over 200000 snps for 340 observations (ids). If I plot the eigenvectors (called rotation in prcomp) 2,3 and 4 (e.g. plot (rotation[,2]) I see a strange "column" in my data (see attachment). I suggest it is an artefact (but of what?). Suggestion: I used prcomp this way: prcomp (mat), where mat is a matrix with the column means already substracted followed by a
2010 Aug 24
3
generate random numbers from a multivariate distribution with specified correlation matrix
Hi all, rmvnorm()can be used to generate the random numbers from a multivariate normal distribution with specified means and covariance matrix, but i want to specify the correlation matrix instead of covariance matrix for the multivariate normal distribution. Does anybody know how to generate the random numbers from a multivariate normal distribution with specified correlation matrix? What about
2006 Oct 24
3
Error when naming rows of dataset
I get the following error when I try reading in a table. How are 1.1, 1.2, 1.3 duplicate row names? Thx. > table <- read.table('latestWithNumber.txt', header=T) Error in "row.names<-.data.frame"(`*tmp*`, value = c("1.1", "1.2", "1.3", : duplicate 'row.names' are not allowed Yongchuan
2007 Feb 19
3
summary polr
Hi all, I have a problem to estimate Std. Error and t-value by ?polr? in library Mass. They result from the summary of a polr object. I can obtain them working in the R environment with the following statements: temp <- polr(formula = formula1, data = data1) coeff <- summary(temp), but when the above statements are enclosed in a function, summary reports the following error:
2011 Jun 21
4
Re; Getting SNPS from PLINK to R
I a using plink on a large SNP dataset with a .map and .ped file. I want to get some sort of file say a list of all the SNPs that plink is saying that I have. ANyideas on how to do this? -- Thanks, Jim. [[alternative HTML version deleted]]
2012 Feb 23
0
creating a loop for multiple file
Hi all, need help very urgently I did stepwise logistic regression for 35 covariates and added one SNP out of (500000) to get the best model for each model As my professor asked me using this command, outfiles <- paste(colnames(snps), ".txt", sep="") # list of output files for the best models for(i in 1:ncol(snps)) { model <- glm (Pheno~var1+var2+var3+..(all
2012 Dec 30
3
Odds Ratio and Logistic Regression
Dear All, I am learning the ropes about logistic regression in R. I found some interesting examples http://bit.ly/Vq4GgX http://bit.ly/W9fUTg http://bit.ly/UfK73e but I am a bit lost. I have several questions. 1) For instance, what is the difference between glm.out = glm(response ~ poverty + gender, family=binomial(logit), data=mydata) and glm.out = glm(response ~ poverty * gender,
2011 Jun 21
1
Getting SNPS from PLINK to R
snpMatrix package is quite nice (read.plink())
2012 Feb 17
3
stepwise selection for conditional logistic regression
 Hi, Is there any function available to do stepwise selection of variables in Conditional(matched) logistic regression( clogit)? step, stepwise  etc are failing in case of conditional logistic regression. Please help.  Thanks P.T. Subha [[alternative HTML version deleted]]
2003 Oct 09
3
Specifying suitable PC to run R
If I am buying a PC where the most compute intensive task will be running R and I do not have unlimited resources what trade-offs should I make? Specifically should I go for 1 - more memory, or 2 - faster processor, or 3 - something else? If it makes a difference I shall be running Windows on it and I am thinking about getting a portable which I understand makes upgrading more difficult. Extra
2011 May 23
6
What are the common Standard Statistical methods used for the analysis of a dataset
Hi, Anybody know what are the common Standard statistical methods used for the analysis of a dataset,and anybody know which of these methods give similar results Ram [[alternative HTML version deleted]]
2007 Mar 21
3
Stepwise Logistic Regression
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2007 Sep 17
1
Stepwise logistic model selection using Cp and BIC criteria
Hi, Is there any package for logistic model selection using BIC and Mallow's Cp statistic? If not, then kindly suggest me some ways to deal with these problems. Thanks. -- View this message in context: http://www.nabble.com/Stepwise-logistic-model-selection-using-Cp-and-BIC-criteria-tf4464430.html#a12729613 Sent from the R help mailing list archive at Nabble.com.
2011 Mar 01
1
Logistic Stepwise Criterion
Dear R-help members, I'd like to run a binomial logistic stepwise regression with ten explanatory variables and as many interaction terms as R can handle. I'll come up with the right R command sooner or later, but my real question is whether and how the criterion for the evaluation of the different models can be set to be the probability of the residual deviance in the Chi-Square
2005 May 07
1
help for bootstrap of backward stepwise logistic regression
I would like to perform a bootstrap validation of a backward stepwise logistic regression analysis, but I am a beginner with R and I am not sure of how to do it. Is there anyone that can send me a sample file in tab format (that I can modify in Excel by pasting my data) and the pertinent R algorithm? Many thanks Giuseppe -- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Dr. Giuseppe Biondi
2011 Nov 30
3
Upgrading R on my EEE PC netbook
I have been successfully been using R on my EEE PC for some while now. Although it uses Xandros I have been able to install various pieces of software by pretending that it was Debian etch. Johannes was kind enough to continue providing binaries on CRAN for a while but I think I am the only person still living in the past as CRAN etch is currently stuck at 2.11.0 and I cannot rely on him to
2008 Jan 21
2
reordering huge data file
Dear R-experts, My problem is how to handle a 10GB data file containing genotype data. The file is in a particular format (Illumina final report) and needs to be altered and merged with phenotype data for further analysis. PERL seems to be an frequently used solution for this type of work, however I am inclined to think it should be doable with R. How do I open a text-file, line by line,