search for: aghmed

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

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

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

...lme which have complex random effects and bootstrapping. By the standards of r-help posters I have small datasets (few thousand cases, few hundred variables). In order to facilitate working with colleagues I need to stick with windows even if linux would be more efficient Michael Dewey med at aghmed.fsnet.co.uk http://www.aghmed.fsnet.co.uk/home.html

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:

...USB stuck but I find the documentation for doing that hard to grasp. You might find it helpful to know that more or less all I know of Linux is gained from reading this list and that I am still at the stage where I regard setting up a symbolic link as a major achievement. Michael Dewey info at aghmed.fsnet.co.uk http://www.aghmed.fsnet.co.uk/home.html

...asking for trained legal advice here, it is the spirit of the rules. 3 - I assume including the .bbl file would be fine rather than making a separate .bib file? I am not envisaging doing anything complex: text, formulae, some tables and one figure plus a few references. Michael Dewey info at aghmed.fsnet.co.uk http://www.aghmed.fsnet.co.uk/home.html

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]]

Hello! I have some data stored into 2 separate csv file. 1 file (called A.csv) (12 results named Group1, Group2, Group3, etc...) odds ratios, 2 file (called B.csv) 12 corresponded errors. How to import that data into R and make forest plot like I saw inside help file Rmeta and meta with included different font colors and names trough X and Y axis. I know for meta libb ... out <-

...nce it took me a few false starts to configure my mailer to do it I have (with the encouragement of the list owner) put together a few hints. All I need now is for people who use other mailers to fill in the details in the same way as I have done for Eudora. The draft is available at http://www.aghmed.fsnet.co.uk/r/digest.htm Any other comments welcome of course. Michael Dewey http://www.aghmed.fsnet.co.uk

consider p as random effect with 5 levels, what is difference between these two models? > p5.random.p <- lmer(Y ~p+(1|p),data=p5,family=binomial,control=list(usePQL=FALSE,msV=1)) > p5.random.p1 <- lmer(Y ~1+(1|p),data=p5,family=binomial,control=list(usePQL=FALSE,msV=1)) in addtion, I try these two models, it seems they are same. what is the difference between these two model. Is

Hi, I need to create the correlation table of a set of categorical data (sex, marital_status, car_type, etc.) for a given population. Basically what I'm looking for is a function like cor( ) working on factors (and, if possible, considering NAs as a level). To better express myself, the manual way should be: 1) to create a set of n-1 numeric dummies (whose assigned values are

..."R & D" > sub("&", "\\\\&", temp) [1] "R \\& D" > So I can get zero, or two backslashes, but not one. I am sure this is really simple but I did not find the answer by doing, for example ?regexp or ?Quotes Michael Dewey http://www.aghmed.fsnet.co.uk

...~ Infl + Type + Cont, housing) where all data is available from MASS, as it is an example in R Help on 'polr'. Results are: Re-fitting to get Hessian Error in eval(expr, envir, enclos) : object "dat" not found Paolo Accadia >>> Michael Dewey <info at aghmed.fsnet.co.uk> 20/02/07 13.43 >>> At 15:21 19/02/2007, Paolo Accadia wrote: >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 environme...

Would like to know how much data can R process - number of rows and columns? [[alternative HTML version deleted]]

Hello, I once used the metawin software to perform a meta-analysis (see metawinsoft, Rosenberg et al.) and produced normal qqplot to test for a potential bias in the dataset. I now want to re-use the same dataset with the package metafor by W. Viechtbauer (great package btw). I run the qqnorm.rma.uni function. I use standardized effect sizes as in metawin. QQplot generated with metafor differs

Hello, I found in the forum two threads about point biserial correlation. One of them (1) mentioned "a point-biserial correlation is just a Pearson correlation where one of the variables is dichotomous. Thus, the command is just the normal cor function". The other (2) mentioned "Professor Fox's package polycor" as a way to calculate point biserial correlation?

Hi all, I am running Stepwise logistic regression and i have : 1- Multiple covatiates included in each model (No missing data) 2- Genotype data (SNPs) about 500,000 . I partitioned the data to multiple files (there are missing data) I run the step by including all the covariates and one SNP at each model. but i got this message : number of rows in use has changed: remove missing values? In

Greetings, I wish to conduct a meta-analysis for which the outcome is a continuous variable measured on the same individuals before and after an intervention. Hence, the comparison is not made between two groups, but within groups, at diffrent times. Each study reports the mean outcome and SD before the intervention and the mean outcome and SD after the intervention. While p-values for

I am looking for an R package with which one can calculate an effect size for a set of contrasts given an omnibus chi-square test statistic (more than 1 degree of freedom). Is there such a package? Presumably, it would implement the procedure (or something like it) described by Roznow and Rosenthal 1996 Psychological Methods 1: 331-340. many thanks! Steven Orzack Fresh Pond Research Institute