[R] Standard errors in regression models with interactions terms

2013-11-09 Thread rm
In a rather simple regression, I’d like to ask the question, for high trees, whether it makes a difference (for volume) whether a three is thick. If my interpretation is correct, for low trees, i.e. for which trees$isHigh == FALSE, the answer is yes. The problem is how to "merge" the standard er

[R] standard errors of marginal effects in multinomial logit

2013-01-20 Thread Kremena Bachmann
Deat R users, I am looking for a way to get standard errors of marginal effects of multinomial logit model. So far I have estimated coeficients of multinomial logit and covariance matrix of coefficients. I also managed to obtain marginal effects. However, I can not find a way to find standard

[R] standard errors in johansen test

2012-12-29 Thread vitaliano.barberio
Hi, I have the very same problem of this here http://grokbase.com/t/r/r-help/111d386yn9/r-standard-errors-in-johansen-test, I replicated all the steps in the Papar: http://cran.r-project.org/web/packages/vars/vignettes/vars.pdf untill here: R> vecm <- ca.jo(Canada[, c("rw",

[R] Standard errors for predictions of zero-inflated models

2012-11-30 Thread Lee, Laura
Dear all, I am using the zeroinfl() function from the pscl package to develop a zero-inflated Poisson GLM. I would like to calculate the standard errors of predicted values. I've tried code posted in a previous discussion on this topic (https://stat.ethz.ch/pipermail/r-help/2008-December/182806

Re: [R] Standard errors GLM

2012-03-13 Thread Rubén Roa
roject.org] En nombre de D_Tomas Enviado el: martes, 13 de marzo de 2012 14:39 Para: r-help@r-project.org Asunto: [R] Standard errors GLM Dear userRs, when applied the summary function to a glm fit (e.g Poisson) the parameter table provides the categorical variables assuming that the first leve

Re: [R] Standard errors GLM

2012-03-13 Thread David Winsemius
On Mar 13, 2012, at 9:38 AM, D_Tomas wrote: Dear userRs, when applied the summary function to a glm fit (e.g Poisson) the parameter table provides the categorical variables assuming that the first level estimate (in alphabetical order) is 0. Not really. It returns an estimate for the cont

Re: [R] Standard errors GLM

2012-03-13 Thread Joshua Wiley
Hi, See inline. On Tue, Mar 13, 2012 at 6:38 AM, D_Tomas wrote: > Dear userRs, > > when applied the summary function to a glm fit (e.g Poisson) the parameter > table provides the categorical variables assuming that the first level > estimate (in alphabetical order) is 0. > > What is the standard

[R] Standard errors GLM

2012-03-13 Thread D_Tomas
Dear userRs, when applied the summary function to a glm fit (e.g Poisson) the parameter table provides the categorical variables assuming that the first level estimate (in alphabetical order) is 0. What is the standard error for that variable then? Are the standard errors calculated assuming

Re: [R] Standard errors from predict.gam versus predict.lm

2012-02-17 Thread Simon Wood
Mike, Isn't this just an example of the wrong model giving a spurious impression of precision? or more accurately, precision at the expense of accuracy? Here's a linear model example of the same thing... set.seed(1) n <- 400 x <- runif(n)-.5 y <- 2+ x*.2+ x^2 + rnorm(n)*.5 m1 <- lm(y~1) m2 <- l

[R] Standard errors from predict.gam versus predict.lm

2012-02-17 Thread Dunbar, Michael J.
I've got a small problem. I have some observational data (environmental samples: abiotic explanatory variable and biological response) to which I've fitted both a multiple linear regression model and also a gam (mgcv) using smooths for each term. The gam clearly fits far better than the lm mod

[R] Standard errors of sexual dimorphism?

2011-09-02 Thread ErikiLund
Hello! I am working on a manuscript on sexual dimorphism in an aquatic invertebrate, where we have estimated sexual dimorphism (SD) for 7 different traits in four populations (a total of 28 SD-estimates). We have used the following formula for estimating SD: 100 * (mean male trait value - mean fem

Re: [R] standard errors in johansen test

2011-01-12 Thread Jorge Ivan Velez
Hi Walter, The paper can be found at http://cran.r-project.org/web/packages/vars/vignettes/vars.pdf It seems that you need the "vars" library before trying the function you mention. What happens if you do the following? install.packages("vars") require(vars) ?cajorls ?ca.jo HTH, Jorge On Wed

[R] standard errors in johansen test

2011-01-12 Thread Walter Zhang
Dear all, I have a question. How to get the standard errors of alpha and beta when using "ca.jo" to test cointergration? In the paper by Bernhard Pfaff and Kronberg im Taunus “VAR, SVAR and SVEC Models: Implementation Within R Package” pp.24-25. The standard errors are listed on the table

[R] standard errors, graphical representation of glmer

2010-04-13 Thread Kay Cichini
hi, i did a binomial glmer for a repeated measure design. now i wanted to use some indicator of variance for the fixed eff. of the model for the graphical representations. sd's of the plain incident rates are huge and misleading in that context. thus i thought of extracting se's of the coefficien

Re: [R] Standard errors from a randomization test?

2010-01-11 Thread David Winsemius
On Jan 8, 2010, at 6:45 AM, jjh wrote: Hello- Is it possible to estimate standard errors for a multiple regression model using a randomization test approach? I have seen a lot on using the procedure to get a test statistic, but nothing that talks about getting actual standard errors. Is

Re: [R] Standard errors from a randomization test?

2010-01-11 Thread jjh
Standard errors for the coefficients. Thanks! Tal Galili wrote: > > Hi jjh, > I wasn't able to understand: for what statistic do you want the standard > error for? (The coefficients, the R^2 ?) > > Tal > > > Contact > Details:--

Re: [R] Standard errors from a randomization test?

2010-01-11 Thread Tal Galili
Hi jjh, I wasn't able to understand: for what statistic do you want the standard error for? (The coefficients, the R^2 ?) Tal Contact Details:--- Contact me: tal.gal...@gmail.com | 972-52-7275845 Read me: www.talgalili.com (Heb

[R] Standard errors from a randomization test?

2010-01-08 Thread jjh
Hello- Is it possible to estimate standard errors for a multiple regression model using a randomization test approach? I have seen a lot on using the procedure to get a test statistic, but nothing that talks about getting actual standard errors. Is this possible? How might I do this in R? Thank

Re: [R] standard errors in bbmle

2009-10-23 Thread Ben Bolker
Peter Dalgaard wrote: > > alexander russell wrote: >> Hello, >> Mle2 is a little unforthcoming in the matter of standard errors? Is there >> a >> way to ask the program to supply standard errors along with estimates in >> cases when it doesn't print them 'voluntarily'? >> regards, >> s > > Wha

Re: [R] standard errors in bbmle

2009-10-23 Thread Peter Dalgaard
alexander russell wrote: > Hello, > Mle2 is a little unforthcoming in the matter of standard errors? Is there a > way to ask the program to supply standard errors along with estimates in > cases when it doesn't print them 'voluntarily'? > regards, > s What did you do? Which "cases"? Did you look a

[R] standard errors in bbmle

2009-10-23 Thread alexander russell
Hello, Mle2 is a little unforthcoming in the matter of standard errors? Is there a way to ask the program to supply standard errors along with estimates in cases when it doesn't print them 'voluntarily'? regards, s [[alternative HTML version deleted]] _

[R] Standard Errors of Coefficients

2009-01-29 Thread Andreas Klein
Hello. I estimated a VAR(1) TSmodel (var_1) with estMaxLik from the dse1 package given a TSdata object (mydata). est.model <- estMaxLik(var_1,mydata) How can I obtain the standard errors for the four coefficients of the estimated model to check for significance? - Is it yet calculated and I ca

Re: [R] Standard errors of least squares adjusted means

2009-01-22 Thread John Fox
age- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On > Behalf Of Bruno Estigarribia > Sent: January-22-09 12:32 AM > To: r-help@r-project.org > Subject: [R] Standard errors of least squares adjusted means > > Hello, > > I have the following model

Re: [R] Standard errors of least squares adjusted means

2009-01-22 Thread Mark Difford
Hi Bruno, Apropos of "ls-means" ... >> I have tried help.search and RSiteSearch with several terms including >> "standard errors", "least square means", "adjusted means". And "ls-means," which is what "you" call them? There are many threads on this, spanning many years. The following, RSiteSe

[R] Standard errors of least squares adjusted means

2009-01-21 Thread Bruno Estigarribia
Hello, I have the following model: lm.7 <- lm(Y ~ F + C1 + C2 , data = EM4) F is a 4-level factor, the rest are covariates centered at their mean (Y is a two-column matrix). I have tried to find functions to give the model-adjusted means (adjusted at the covariates'means) and their standard dev

Re: [R] standard errors for predict.nls?

2008-11-12 Thread Ben Bolker
nts(st$conc,predict(puro1),pch=2,col="red") > # > isn't that what we want graphically and t(qq) gives us the values > obviously quantile can be used with any set of p's > [EMAIL PROTECTED] > > > -Original Message- > From: [EMAIL PROTECTED] on behalf of Ben

Re: [R] standard errors for predict.nls?

2008-11-12 Thread R Heberto Ghezzo, Dr
nd t(qq) gives us the values obviously quantile can be used with any set of p's [EMAIL PROTECTED] -Original Message- From: [EMAIL PROTECTED] on behalf of Ben Bolker Sent: Tue 11/11/2008 3:09 PM To: [EMAIL PROTECTED] Cc: r-help@r-project.org Subject: Re: [R] standard errors for predict.nls

Re: [R] standard errors for predict.nls?

2008-11-11 Thread Ben Bolker
Here's how far I've gotten. It's a start, but I can't so far find a way to extract the actual thing we want -- the bootstrap confidence intervals on the predictions. I apologize for not taking the time to go read up on the boot library etc. etc. (I *have* RTFM, but I haven't backtracked to th

Re: [R] standard errors for predict.nls?

2008-11-09 Thread Rolf Turner
On 7/11/2008, at 11:33 PM, Christoph Scherber wrote: Dear all, I would like to get standard errors (or confidence intervals) for *predicted* values from an nls fit. I have tried to implement code from p.225 in MASS (bootstrapping a nls fit), but this gives only the confidence intervals o

Re: [R] standard errors for predict.nls?

2008-11-07 Thread Christoph Scherber
Dear all, I would like to get standard errors (or confidence intervals) for *predicted* values from an nls fit. I have tried to implement code from p.225 in MASS (bootstrapping a nls fit), but this gives only the confidence intervals of the parameter estimates, but not an overall confidence in

Re: [R] standard errors for predict.nls?

2008-11-06 Thread Christoph Scherber
Dear Prof Ripley, Am I correct if I use the following code to get c.i.´s for predicted values of the nls fit: puro1<-nls(rate~a*conc/(b+conc), data=Puromycin[1:12,], start=list(a=200, b=1)) #set up nls model # assume only one predicted value is obtained using predict(puro1,list(conc=0.02)):

Re: [R] standard errors for predict.nls?

2008-11-04 Thread Prof Brian Ripley
On Mon, 3 Nov 2008, Ben Bolker wrote: Prof Brian Ripley wrote: Christoph Scherber agr.uni-goettingen.de> writes: Dear all, Is there a way to retrieve standard errors from nls models? The help page tells me that arguments such as se.fit are ignored... Many thanks and best wishes Christoph

Re: [R] standard errors for predict.nls?

2008-11-03 Thread Ben Bolker
Prof Brian Ripley wrote: >> Christoph Scherber agr.uni-goettingen.de> >> writes: >> >>> >>> Dear all, >>> >>> Is there a way to retrieve standard errors from nls models? >>> The help page tells me that arguments >>> such as se.fit are ignored... >>> >>> Many thanks and best wishes >>> Christoph >

Re: [R] standard errors for predict.nls?

2008-11-03 Thread Prof Brian Ripley
On Mon, 3 Nov 2008, Ben Bolker wrote: Christoph Scherber agr.uni-goettingen.de> writes: Dear all, Is there a way to retrieve standard errors from nls models? The help page tells me that arguments such as se.fit are ignored... Many thanks and best wishes Christoph I have written some rea

Re: [R] standard errors for predict.nls?

2008-11-03 Thread Christian Ritz
Dear Christoph, using the package 'alr3' it's not difficult! Have a look at the following example: ## Fitting a Michaelis-Menten model Puromycin.m1<-nls(rate~a*conc/(b+conc), data=Puromycin[1:12,], start=list(a=200, b=1)) library(alr3) ## Predictions (with standard errors) at concentrations 0

Re: [R] standard errors for predict.nls?

2008-11-03 Thread Ben Bolker
Christoph Scherber agr.uni-goettingen.de> writes: > > Dear all, > > Is there a way to retrieve standard errors from nls models? > The help page tells me that arguments > such as se.fit are ignored... > > Many thanks and best wishes > Christoph I have written some reasonably generic delta-

[R] standard errors for predict.nls?

2008-11-03 Thread Christoph Scherber
Dear all, Is there a way to retrieve standard errors from nls models? The help page tells me that arguments such as se.fit are ignored... Many thanks and best wishes Christoph -- Dr. rer.nat. Christoph Scherber University of Goettingen DNPW, Agroecology Waldweg 26 D-37073 Goettingen Germa

Re: [R] standard errors

2008-02-28 Thread Bill.Venables
Subject: [R] standard errors Hi, guess my problem has simple solution. I want to extract ONLY Std. Errors of Max. Lik. estimates (my_fit<-mle(object,...)), the same as I can do with estimates by: x<-as. matrix(coef(my_fit)). I could not find any function similar to 'coef(my_fit)', whi

Re: [R] standard errors

2008-02-28 Thread Duncan Murdoch
threshold wrote: > Hi, guess my problem has simple solution. > I want to extract ONLY Std. Errors of Max. Lik. estimates > (my_fit<-mle(object,...)), the same as I can do with estimates by: > x<-as. matrix(coef(my_fit)). > I could not find any function similar to 'coef(my_fit)', which extracts onl

Re: [R] standard errors

2008-02-28 Thread Henrique Dallazuanna
Try this: coef(summary(fit))[,2] On 28/02/2008, threshold <[EMAIL PROTECTED]> wrote: > > Hi, guess my problem has simple solution. > I want to extract ONLY Std. Errors of Max. Lik. estimates > (my_fit<-mle(object,...)), the same as I can do with estimates by: > x<-as. matrix(coef(my_fit)). >

Re: [R] standard errors

2008-02-28 Thread Achim Zeileis
On Thu, 28 Feb 2008, threshold wrote: > Hi, guess my problem has simple solution. > I want to extract ONLY Std. Errors of Max. Lik. estimates > (my_fit<-mle(object,...)), the same as I can do with estimates by: > x<-as. matrix(coef(my_fit)). > I could not find any function similar to 'coef(my_fit)

[R] standard errors

2008-02-28 Thread threshold
Hi, guess my problem has simple solution. I want to extract ONLY Std. Errors of Max. Lik. estimates (my_fit<-mle(object,...)), the same as I can do with estimates by: x<-as. matrix(coef(my_fit)). I could not find any function similar to 'coef(my_fit)', which extracts only Standard Errors. So far

[R] Standard errors of sample autocorrelations

2007-10-28 Thread Strong
Dear All Is there a way to extract the standard errors of sample autocorrelations after using acf function to estimate the autocorrelations. If yes, what method is the calculation of standard errors based on? Thanks in advance for your time and help. Strong ___

Re: [R] standard errors of regression coefficients

2007-10-03 Thread Jeffrey Robert Spies
stderr_int <- summary(lm(y ~ x))$coefficients[1,2] stderr_slope <- summary(lm(y ~ x))$coefficients[2,2] Jeff. On Oct 3, 2007, at 3:01 AM, Alexander Moreno wrote: > Hi, > > If I have two vectors x and y and I do lm(y~x) and now I want to > define > variables that are the standard errors of the

[R] standard errors of regression coefficients

2007-10-03 Thread Alexander Moreno
Hi, If I have two vectors x and y and I do lm(y~x) and now I want to define variables that are the standard errors of the slope and intercept, how do I do that? Thanks, Alex [[alternative HTML version deleted]] __ R-help@r-project.org mailing