search for: bonofiglio

...the mechanism underlying the procedure of NUMBER RADOMIZATION. could anyone of you, masters, attach me the algorithm (or source code? is it right?) behind the *sample()* function, so i can inspect in detail the mechanism of this so gossiped "radomization"? thank you, sincerely federico bonofiglio, student of statistics at milano bicocca university, italia [[alternative HTML version deleted]]

Hello everybody!!!! Quick question, if you'd like to throw a little tip: does anyone knows a function that runs piecewise regression models with coefficients estimation and inferences ? Thank you [[alternative HTML version deleted]]

...y freak..!! ...I'M scared !!! > ?mean Errore: non trovo la funzione "?" > ?rbinom Errore: non trovo la funzione "?" > There is something right here that I'm (hopefully) missing , or is ti just a bad dream!!??? Thank u if anyone wish a quick advise.. Federico Bonofiglio [[alternative HTML version deleted]]

...bing results: The predicted stright line after the break point is not straight at all, instead behaves like if it was a hig order polynomial or something similar!!!! I attach the codes below, hoping someone can point me the mistake.... I sincerely express many thanks in advance ...... Federico Bonofiglio frame3<-data.frame(id,chol,cd4,rt,sex,age, nadir,pharmac2,hbs,hcv,resp2, hivbl,switch) # I run a model specifing the function (t-t*)+ = 0 if t<=t* AND (t-t*)+ = t if t>t* with the following syntax, emulating MJ Crawley (The R book 2007, Wiley), # rt+rt*(rt>15) I run the...

Hi folks... check this out.. > GLU<-lme(gluc~rt*cd4+sex+age+rf+nadir+pharmac+factor(hcv)+factor(hbs)+ + haartd+hivdur+factor(arv), + random= ~rt|id, na.action=na.omit) > intervals(GLU)$fixed lower est. upper (Intercept) 67.3467070345 7.362307e+01 7.989944e+01 rt *0.0148050160* 6.249304e-02 1.101811e-01 cd4

...00) ) fit <- predict(mod,data.frame(rd=giorni,k=esplic)) graph <- persp(x=giorni, y=esplic,fit, expand=0.5, ticktype="detailed", theta=-45) #error : z argument not valid I would be grateful if someone would give me some suggestions. Thank u again and happy new year Federico Bonofiglio [[alternative HTML version deleted]]

...uped by by a general nesting structure that sets factorA1 and factorA2 as same level effects (hence non nested) and factorB as nested in both. I also must express my momentaneous sheer ignorange on the pdMat objects, thing that prabably is not helping me in the process Kindly Regards Federico Bonofiglio [[alternative HTML version deleted]]

Hello Masters, I run the loess() function to obtain local weighted regressions, given lowess() can't handle NAs, but I don't improve significantly my situation......, actually loess() performance leave me much puzzled.... I attach my easy experiment below #------SCRIPT---------------------------------------------- #I explore the functionalities of lowess() & loess() #because I have

...t? - degrees of freedom exponentiate dramatically (one per cell) , so may I risk to never obtain a significant result? I also take the chance to ask wheater u know any implemented method to plot logistic curves directly out of a glm() model I would like to thank u all by the way Federico Bonofiglio [[alternative HTML version deleted]]

Dear Masters, I have a question to submit consider the following script m<-4.95 obs<-rpois(36,m) # i generate 36 realization from a poisson(m) hist(obs,freq=F) curve(dpois(x,m),add=T,col="red") #i wish to overlay on the histogram the theorical poisson density function errors are returned saing the x vector doesn't contain integers.... really bizarre i can't give

Hi dears while modeling an interaction random effect in lmer i receive the instantaneous error message > ldlM4<-lmer(ldl~rt*cd4+age+rf+pharmac+factor(hcv)+ + hivdur+(rt:cd4|id),na.action=na.omit,REML=F) *Warning message: In mer_finalize(ans) : false convergence (8) * I think the matter lies in syntax, 'cause i sistematically receive the same message even when changing response... PS:

Hi Dears, When I introduce an interaciton in a piecewise model I obtain some quite unusual results. If that would't take u such a problem I'd really appreciate an advise from you. I've reproduced an example below... Many thanks x<-rnorm(1000) y<-exp(-x)+rnorm(1000) plot(x,y) abline(v=-1,col=2,lty=2) mod<-lm(y~x+x*(x>-1)) summary(mod) yy<-predict(mod)

hello R-masters. i have an R-issue here that i don't know if you'd wish to help me? about it: briefly i'd like to generate many (say hundred) realizations of a random walk, execute a few operations on each of them (mean time of return), and graph each realization on the same plot. IN OTHER WORDS I'D LIKE TO IMPOSE A LOOPING CYCLE TO THE COMMAND NOT THE ARGUMENT OF THE COMMAND.

...uped by by a general nesting structure that sets factorA1 and factorA2 as same level effects (hence non nested) and factorB as nested in both. I also must express my momentaneous sheer ignorange on the pdMat objects, thing that prabably is not helping me in the process Kindly Regards Federico Bonofiglio [[alternative HTML version deleted]] ------------------------------ Message: 71 Date: Fri, 21 Jan 2011 15:33:56 -0500 From: las65@buffalo.edu To: <r-help@r-project.org> Subject: [R] building package Message-ID: <19068.1295642036@buffalo.edu> Content-Type: text/plain; charset...

Hi dears, I do > CHOL<-lme(chol~rt*cd4+sex+age+rf+nadir+pharmac+factor(hcv)+factor(hbs)+ haartd+hivdur+factor(arv), random= ~rt|id, na.action=na.omit) ...runs sweet,..then ....try a multicomparisons approach for the categorical rf > summary(glht(CHOL, linfct=mcp(rf="Tukey"))) * Error in model.frame.default(object, data, xlev = xlev) : l'oggetto non è una matrice

Dear Masters, I'm driving crazy with the lowess() function.... my intent is smoothing confidence intervals for predicted y values in a linear model lm() setting since in the predict() function there exists an option for predicting NA values, I instead encounter problems when I fit a missing values x variable to the predicted terms.....,impossible task!!! I've been banging on my head