similar to: covariance matrix of predictions

Hi, I installed the package Hmisc with the command install.packages("Hmisc") without errors. When I try to load the library with command library(Hmisc) I get the error > library(Hmisc) Error in library(Hmisc) : there is no package called 'Hmisc' > version _ platform i386-pc-linux-gnu arch i386 os linux-gnu system i386,

Dear all, I tried to use "step" function to do model selection, but I got an error massage. What I don't understand is that data as data.frame worked well for my other programs, how come I cannot make it run this time. Could you please tell me how I can fix it? ***************************************************************************************************

Hello, I was wondering if I can plot two curves I get from "density(data)" into one plot. I want to compare both. With the following commad, I just get one curve plotted: plot( density(mydata) ) Sorry for this stupid question but I could not find a solution until now... Antje

Dear all, I want to design a histogram and I need to have the frequency at certain points. For example I have the following 2 columns: *X Y* 0.1 25 0.4 22 0.45 11 0.55 21 I want the chart to have 4 columns. First column is from 0.0-0.1 (on X) and frequency is 25. Next colum is wider and form 0.1-0.4 with 22 frequency. Next column is narrow with 11 frequency and the last column is

I was reading about the project drawer feature in Textmate, which is Mac only. Is there a similar feature in a Windows based text editor that works with R. This feature sounds really useful. Thanks, Graham [[alternative HTML version deleted]]

Hi, Suppose I have a multivariate response Y (n x k) obtained at a set of predictors X (n x p). I would like to perform a linear regression taking into consideration the covariance structure of Y within each unit - this would be represented by a specified matrix V (k x k), assumed to be the same across units. How do I use "lm" to do this? One approach that I was thinking of

Hi, Sorry for the question, I know it should be basic knowledge but I'm struggling for two hours now. How do I select only the first entry of each list member and ignore the rest? So for > $"121_at" > -113691170 > $"1255_g_at" > 42231151 > $"1316_at" > 35472685 35472588 > $"1320_at" > -88003869

Hi! I was trying to implement a probit model on a dichotomous outcome variable and found that the predictions were outside the (0,1) interval that one should get. I later tried it with some simulated data with a similar result. Here is a toy program I wrote and I cant figure why I should be getting such odd predictions. x1<-rnorm(1000) x2<-rnorm(1000) x3<-rnorm(1000)

Hi R users I have a dataset which represents points that are market by patients as the source of pain. Basically the patients indicates by a cross on a chest pictures where he/she thinks is the source of pain. The data was then digitalized by divinding the chest into small squares and each square was give value 1 if it was the center 2 if it was touched by the markings and 3 if it was not

HI ! I?ve installed the latest R version (2.3.1) and I?ve had problems to save my graphics as JPEG, PNG and the others available formats. R saves the file with no extension. Then, I have to open this file using an image visualizer and save it as PNG, for instance. Previous R versions work without problems. Has everyone had a similar problem? Is it a bug of R 2.3.1? Thanks in advance. Ilka

Hi All, I need some help in how one can implement maximumlikelihood estimation for models with discrete hidden variables in EM in R. Regards [[alternative HTML version deleted]]

Hello All, I have 8 variables named a b c d e f g h I need to create four variables from these 8 vraibles in R. the new variables are ab,cd,ef,gh. Can anyone pleas help me thanks, Pratap --------------------------------- [[alternative HTML version deleted]]

hie when i use plot.survfit to plot more than one graph why I only see the last graph how do i see the other graphs.for example n=20 n1=n/2 n2=n/4 a11=4;a12=4 ;a21=4 ;a22=4 t1<-array(1,c(n1)) t2<-array(2,c(n1)) treatgrp=matrix(c(t1,t2))

I would like to buy a basic statistics book (experimental design, sampling, ANOVA, regression, etc.) with examples in R. Or download it in PDF or html format. I went to the CRAN contributed documentation, but there were only R textbooks, that is, textbooks where R is the focus, not the statistics. And I would like to find the opposite. Other text I am trying to find is multivariate data

Hi R users, I am looking to numerically solve a dynamic program in the R environment. I was wondering if there were people out there who had expereinced success at using R for such applications. I'd rather continue in R than learn Mathlab. A concern that has been cited that may discourage R use for solving dynamic programs is its memory handling abilities. A senior researcher had a lot of

Hello, I am interested in plotting my regression analysis results(regression coefficients and standard errors obtained through OLS and Tobit models) in the form of graphs.What is the best way to accomplish this? Thanks. Murali Kuchibhotla [[alternative HTML version deleted]]

Hello, I need to write out a data matrix as a STATA 7 file and this happens perfectly with write.dta(), except I cannot seem to export the labelnames to Stata. So far I have tried the following: # X is the data matrix that is to be exported attributes(X)$var.labels <- c("apple", "banana", "cat") write(X, filename = "text.dta", version = 7) When i

I''m looking for a R function which can maximise this logliklihood function, under the constraits a>0 e b>0 f<-function(param){ a<-param[1] b <-param[2] log(prod)-(a*s2)-(b*s)-n*log(1-((0.5*b/sqrt(a))*(exp((b^2)/(4*a)))*((sqrt(pi ))*(1-pnorm(-b/(2*sqrt(a)), mean=0, sd=1)))))} I''ve tried maxlik constrOptim e donlp2 but without success. Thanks so

Hi All, Please pardon me if I am missing something obvious here. How do I get the Kaplan-Meier estimate function that is created by survfit and plotted by the code. fit <- survfit(Surv(time, status) , data=aml) plot(fit) That is, I need a function that will give me the survival estimate at a given time: \hat{S}(t). Thanks in advance. Ritwik Sinha ritwik.sinha at gmail.com | +12033042111 |

Hi everyone, I'm using the function 'HWE.exact' of 'genetics' package to compute p-values of the HWE test. My data set consists of ~600 subjects (cases and controls) typed at ~ 10K SNP markers; the test is applied separately to cases and controls. The genotypes are stored in a list of 'genotype' objects, all.geno, and p-values are calculated inside the loop over all