similar to: Implementing EM Algorithm in R!

Displaying 20 results from an estimated 3000 matches similar to: "Implementing EM Algorithm in R!"

2006 Nov 26
1
problem loading package Hmisc
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,
2006 Jun 14
3
A question about stepwise procedures: step function
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? ***************************************************************************************************
2006 Aug 23
5
two density curves in one plot?
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
2006 Sep 27
2
Histogram
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
2006 Aug 23
1
covariance matrix of predictions
Hi ! I am trying to get at the covariance of the predictions of a linear model. Suppose the we have: > x<-runif(1000) > y<-2 + 25x*x +rnorm(1000) > lm1 <-lm(y~x, data = data.frame(y = y, x=x)) > x.pred <-runif(10) > y.hat <- predict(lm1, newdata = data.frame(x=x.pred)) I was wondering how to get an estimate of the covariance of y.hat which would be a 10 x 10
2006 Sep 30
3
Textmate project drawer: is there a Windows alternative?
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]]
2006 Oct 27
2
Multivariate regression
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
2006 Sep 29
6
List-manipulation
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
2006 Jun 14
2
Saving R graphics with version 2.3.1
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
2006 Sep 26
2
creation of new variables
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]]
2006 Aug 04
2
plotting picture data
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
2007 Oct 29
3
using survfit
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))
2006 Sep 20
8
Statitics Textbook - any recommendation?
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
2006 Jun 05
3
Fastest way to do HWE.exact test on 100K SNP data?
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
2006 Jun 05
1
negative binomial: expected number of events?
Hi I'm fitting poisson and negative binomial distributions to event data. I'm interested in the expected number of events occuring in a time period. For the poisson this is determined by the parameter lambda only. For the neg. binomial, is the expected number of events determined by the parameter "mu" only or does parameter "size" influence the first moment as
2008 Jul 25
2
graphing regression coefficients and standard errors
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]]
2008 Jul 25
3
Maximization under constraits
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
2008 Dec 06
1
Kaplan-Meier function from survfit
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 |
2006 Jun 02
3
lm() variance covariance matrix of coefficients.
Hi, I am running a simple linear model with (say) 5 independent variables. Is there a simple way of getting the variance-covariance matrix of the coeffcient estimates? None of the values of the lm() seem to provide this. Thanks in advance, Ritwik Sinha rsinha@darwin.cwru.edu Grad Student Case Western Reserve University [[alternative HTML version deleted]]
2004 Feb 02
4
for loops?
Hello R people! How can one use a for loop (or something similar) in R? As I type in each line, I get syntax errors... I'm just confused how much to type in at each ">" prompt. Thanks for your help, cathy ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Catherine M. Stein Research Assistant, Tuberculosis Research Unit Doctoral Candidate in