search for: bonoricus

Displaying 16 results from an estimated 16 matches for "bonoricus".

2008 Mar 12
4
hello! i need help for a specific graphic issue
hello, ladyes and gentlemans. check this: means<-c(4,6,8) stand.error<-c(0.1,0.3,0.5) now i've strongly tryed to scatterplot the means(y-axis),by showing their sd with the arrow(..,code=3,angle=90) function. The problem is that my x-axis has categorical values (say, factor(x)), and the arrows() can't recognize them as right coordinates. ????? thank you all in advance B.F. insubria
2011 Jan 14
4
piecewise regression
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]]
2010 Oct 17
2
dpois().......bizarre warning messages
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
2011 Feb 08
3
intervals {nlme} lower CI greater than upper CI !!!????
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
2011 Mar 19
1
strange PREDICTIONS from a PIECEWISE LINEAR (mixed) MODEL
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)
2010 Oct 26
2
anomalies with the loess() function
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
2010 Dec 29
1
logistic regression with response 0,1
Dear Masters, first I'd like to wish u all a great 2011 and happy holydays by now, second (here it come the boring stuff) I have a question to which I hope u would answer: I run a logistic regression by glm(), on the following data type (y1=1,x1=x1); (y2=0,x2=x2);......(yn=0,xn=xn), where the response (y) is abinary outcome on 0,1 amd x is any explanatory variable (continuous or not)
2008 Jun 03
0
problems on plotting adjacent bars with barplot. Help request, please
hi ladyes and gentlemans of the R comunity. i have the following graphical issue: # say y is a matrix or a dataframe with dim(51,nrow=17),hence 3 columns; l<-51 # now the 3 colums represents 3 different aspects of my continuous variable (3 factors),plotted against a categorical one; n<-levels(factor(x)) # i want to plot those 3 factors adjacently using the barplot(), and possibly show
2010 Jan 15
1
the sample() function
hello R-Wizards!!!!! again i'm invoking your presence!! since all the fuss about the paradoxes on a computer algorithm generating "caos" or un-determinancy, i recently grew quite curious about 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
2011 Feb 08
0
glht{multcomp} : use with lme {nlme}
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 รจ una matrice
2009 Mar 29
1
problems importing file
hi ladies and gentlemen of the R community. i'm federico an italian student of statistics and i've got an issue to submit to you: i've got a huge file.txt replenished of blank values (over a milion of them). by importing it into R the read.table() function higlights missing objects per row and declares an error. there's any way i can detail into the read.table() function to
2010 Oct 25
1
lowess() won't handle NAs
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
2011 Feb 06
1
random interaction effect in lmer
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:
2011 Mar 18
1
PREDICTIONS from a PIECEWISE LINEAR (mixed) MODEL: THEY AIN'T LINEAR BETWEEN BREAK POINTS!!
I Dears, if that wouldn't take u too much effort I'd like to ask for a swift opinion: I have a alinear (mixed effect) model that I wish to run as a piecewise one. When I predict the values Iget quite some odds and disturbing 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
2009 Dec 04
1
cycling k times a realization of a random walk.....problems..
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.
2011 Jan 12
1
graphics: 3D regression plane
Hello Masters, wishing you all a great 2011 I was also going to ask if anyone knows a quick and efficient way to plot a regression plane (z~x*y). I have tried the regr2.plot{HH} function but it is only an educational tool and has poor graphical properties. I also tried to run the following script on a fictitious longitudinal problem, with poor results set.seed(1234)