search for: dobson

Hello: I am trying to understand why glm() does not replicate the results in Dobson, "Introduction to Generalized Linear Models," pp. 17-20. I set up the following model. The variable CONDT is assumed as Poisson and the objective is to estimate the expected value. The data (chronic medical conditions among women in Australia) is as follows: CONDT <- c(0, 1, 1,...

I want to access a file on a ftp-server with R. But it doesn't work. I suppose the reason is the username and password. Here the non working file path ftp://woudc:woudc*@ftp.tor.ec.gc.ca/Archive-NewFormat/totalozone_1.0_1/stn035/dobson/1929/19290301.dobson.beck.002.smi.csv I tested other files on this server, same result: a crash of R. I tested it with other 'normal' sites (on other servers): that works gruess joerg -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list --...

...ate the residuals for a poisson GLM with simulated data; x<-rpois(1000,5) model<-glm(x~1,poisson) my.resids<-(log(x)- summary(model)$coefficients[1]) plot(my.resids,residuals(model)) This shows that my calculated residuals (my.resids) are not the same as residuals(model). p 65 of Annette Dobson's book says that GLM (unstandardised) residuals are calculated by analogy with the Normal case. So where am I going wrong? Thanks for your attention. Martin. Martin Hoyle, School of Life and Environmental Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK Webpage:...

...rate a *.tex file with the output of an OLS estimation. Some people suggested to use the latex function on the Hmisc package. I'm having a bit of trouble to properly specify this function (I'm not a very experienced R user). Below you will find an example, of what I'm doing. ## Annette Dobson (1990) "An Introduction to Generalized Linear Models". ## Page 9: Plant Weight Data. summary(lm.D90 <- lm(weight ~ group - 1))# omitting intercept out <- latex(lm.D90) latex(out, model1, file="") When I run this code, I get an output which does not attend my needs. Firs...

Does anyone know what algorithm R uses in glm, family=binomial (i.e. a logit model)? I assume that it's in the source somewhere, but I wasn't able to find it. I'd like to know what file it's in (in a unix distribution of R). Thanks for your help. --------------------------- Barnet Wagman wagman at enteract.com 1361 N. Hoyne, 2nd floor Chicago, IL 60622 773-645-8369

In glm, is there a way to specify the family to be exponential, or Gamma but with alpha=1? This is required by Dobson Exercise 4.3d, page 48. But without specifying alpha=1, the asnwer is the same as in the book. If reply to the list, please cc me a copy. Thanks. -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ...

...ocess of fitting linear models where the names of variables of models are produced and stored in character vectors. But I have problems to pass the vectors to the lm( ) because I don't know how to strip the quotation marks automatically. Here are the codes of the example of lm( ): ## Annette Dobson (1990) "An Introduction to Generalized Linear Models". ## Page 9: Plant Weight Data. ctl <- (4.17,5.58,5.18,6.11,4.50,4.61,5.17,4.53,5.33,5.14) trt <- (4.81,4.17,4.41,3.59,5.87,3.83,6.03,4.89,4.32,4.69) group <- gl(2,10,20, labels=c("Ctl","Trt")) weight <-...

Dear list, I've noticed that influence.measures and cooks.distance gives different results for non-gaussian GLMs. For example, using R-1.9.0 alpha (2003-03-17) under Windows: > ## Dobson (1990) Page 93: Randomized Controlled Trial : > counts <- c(18,17,15,20,10,20,25,13,12) > outcome <- gl(3,1,9) > treatment <- gl(3,3) > glm.D93 <- glm(counts ~ outcome + treatment, family=poisson()) > influence.measures(glm.D93)$infmat[, 8] 1 2...

...> #0.0 [mp2 @ 0xb7d352f0]Sampling rate 640000 is not allowed in mp2 Error while opening codec for output stream #0.0 - maybe incorrect parameters such as bit_rate, rate, width or height tim at freee-meee:~/dmc/call recordings$ Has anyone got any suggestions based on previous experience? www.tdobson.net ---- If each of us have one object, and we exchange them, then each of us still has one object. If each of us have one idea, and we exchange them, then each of us now has two ideas. - George Bernard Shaw

...cussion? Two factor ANOVA repeated measures design. Each subject gives a percent correct. I am assuming the correct way to proceed is to fit a generalized linear model with binomial responses and logistic link. But I have not found a detailed discussion of this in either McCullagh & Nelder or Dobson. Here is a toy example. Each datum is proportion correct out of 100 trials for one subject: b1 b2 a1 .5,.6 .1,.2 a2 .7,.8 .2,.3 a3 .8,.9 .3,.4 (2 subjects) How does the analysis proceed? Thanks very much for any help. Bill Simpson -.-.-.-.-.-.-.-.-.-.-.-.-.-.-...

Howdy, I looked at the references in the R and S-Plus literature to find a good introduction/reference to GLM. When I then went to Amazon it seemed to me that all the recommended books are out of print. Can anyone give me a recommendation which _available_ book to get? --Ragnar -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read

...unclear what "labels" means - same variable names, or same levels for factor variables. Change "variables specified with the same labels" to "variables with the same names". -------------------------------------------------- Section 11.6 There is a newer version of Dobson, 2002, second edition. Dobson is referenced later, in Section 11.7.2. I don't have the new copy, can't tell you new page numbers. -------------------------------------------------- Section 12.1 Change "High-level plotting commands always start a new plot, erasing the current plot if...

Dear all, I've tried to solve the Es. 12, cap 4 of "Introduction to GLM" by Annette Dobson. It's about the relationship between survival time of leukemia patients and blood cell count. I tried to fit a model with exponential distribution, first by glm (family gamma and then dispersion parameter fixed to 1) and then with survreg. They gave me the same point estimates but the standard...

..."LevelB"), row.names = c("1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12"), class = "data.frame") representing data from @BOOK{Dobson02, author = {Annette J. Dobson}, year = 2002, title = {An Introduction to Generalized Linear Models}, edition = {2.}, publisher = {Chapman \& Hall/CRC}, address = {Boca Raton, Florida, 33431} } page 101. To reproduce the estimates c(6.7,0.75,1.75,-1.0,0.4,1.5) given on page 103 in...

I don't have a copy of Dobson (1990) from which the glm.D93 example is taken in example("glm"), but I'm strongly suspecting that these are made-up data rather than real data; the means of the responses within each treatment are _identical_ (equal to 16 2/3), so two of the parameters are estimated as being zero (wi...

...aunhofer, Germany o Omar Rana, Cardiff University, UK o Ozalp Babaoglu, University of Bologna, Italy o Rajkumar Buyya, Manjrasoft, Australia o Renato Figueiredo, University of Florida, USA o Ricardo Bianchini, Rutgers University, USA o Ron Brightwell, Sandia National Labs, USA o Simon Dobson, University of St Andrews, UK o Tamer Aboualy, IBM Corporation, Canada o Wu Feng, Virginia Tech University, USA * Demos/Exhibits Chair: o Katerina Goulioutkina, IBM Corporation, Canada * Workshop/Tutorial Chair: o Simon Dobson, University of St Andrews, UK * CloudComp Summit Chair: o...

...aunhofer, Germany o Omar Rana, Cardiff University, UK o Ozalp Babaoglu, University of Bologna, Italy o Rajkumar Buyya, Manjrasoft, Australia o Renato Figueiredo, University of Florida, USA o Ricardo Bianchini, Rutgers University, USA o Ron Brightwell, Sandia National Labs, USA o Simon Dobson, University of St Andrews, UK o Tamer Aboualy, IBM Corporation, Canada o Wu Feng, Virginia Tech University, USA * Demos/Exhibits Chair: o Katerina Goulioutkina, IBM Corporation, Canada * Workshop/Tutorial Chair: o Simon Dobson, University of St Andrews, UK * CloudComp Summit Chair: o...

...aunhofer, Germany o Omar Rana, Cardiff University, UK o Ozalp Babaoglu, University of Bologna, Italy o Rajkumar Buyya, Manjrasoft, Australia o Renato Figueiredo, University of Florida, USA o Ricardo Bianchini, Rutgers University, USA o Ron Brightwell, Sandia National Labs, USA o Simon Dobson, University of St Andrews, UK o Tamer Aboualy, IBM Corporation, Canada o Wu Feng, Virginia Tech University, USA * Demos/Exhibits Chair: o Katerina Goulioutkina, IBM Corporation, Canada * Workshop/Tutorial Chair: o Simon Dobson, University of St Andrews, UK * CloudComp Summit Chair: o...

...aunhofer, Germany o Omar Rana, Cardiff University, UK o Ozalp Babaoglu, University of Bologna, Italy o Rajkumar Buyya, Manjrasoft, Australia o Renato Figueiredo, University of Florida, USA o Ricardo Bianchini, Rutgers University, USA o Ron Brightwell, Sandia National Labs, USA o Simon Dobson, University of St Andrews, UK o Tamer Aboualy, IBM Corporation, Canada o Wu Feng, Virginia Tech University, USA * Demos/Exhibits Chair: o Katerina Goulioutkina, IBM Corporation, Canada * Workshop/Tutorial Chair: o Simon Dobson, University of St Andrews, UK * CloudComp Summit Chair: o...

...> > Mira la ayuda del wald.test() para entender lo que te piden... > Tienes que proporcionar los coeficientes del modelo, la matriz de > covarianzas y los términos del modelo sobre los que quieres aplicar el test. > > Este es un ejemplo: > > require(graphics) > ## Annette Dobson (1990) "An Introduction to Generalized Linear Models". > ## Page 9: Plant Weight Data. > ctl <- c(4.17,5.58,5.18,6.11,4.50,4.61,5.17,4.53,5.33,5.14) > trt <- c(4.81,4.17,4.41,3.59,5.87,3.83,6.03,4.89,4.32,4.69) > group <- gl(2, 10, 20, labels = c("Ctl",&quot...