similar to: White's test again

Hi all, I'm running White's test to correct for non-constant error variance and I am using the Anova function in the package CAR. My command structure is > Anova(scireg3, white.adjust="hc3") where scireg3 is an object from lm. I get the message "Error in SS[i] <- SS.term(names[i]) : nothing to replace with" What does this mean and how do I fix it. Thanks

Hi all, In using the identify command, I get the following message > plot(hatvalues(scireg3)) > abline(h=.0154,lty=2) # plots a reference line at (k + 1)/n > identify(1:1165, hatvalues(scireg3),row.names(sciach)) Error in xy.coords(x, y) : 'x' and 'y' lengths differ which doesn't allow me to see the observation number when I scroll over with the mouse. What

Hello Is there any function to calculate White's standard errors in R in an NLS regression. The sandwich and car package do it but they need an lm object to calculate the error's. Does anyone have idea how to do it for an NLS object ? Regards The woods are lovely, dark and deep But I have promises to keep And miles before I go to sleep And miles before I go to sleep ----- [[alternative

Hi I am actually running the White test for correcting Heteroscedasticity. I used sandwich() & car(), however the output shows the updated t test of coefficients, with revised Standard Errors, however the estimates remained same. My problem is that the residuals formed a pattern in the original regression equation. After running the White's test, I got some new standard errors - but

Dear all, Sorry if this is too obvious. I am trying to fit my multiple regression model using lm() Before starting model simplification using step() I checked whether the model presented heteroscedasticity with ncv.test() from the CAR package. It presents it. I want to correct for it, I used hccm() from the CAR package as well and got the Heteroscedasticity-Corrected Covariance Matrix. I am not

Hello. I try to compute a "White-corrected" ANOVA. Therefore I use the command "Anova" implemented in the car()-package): Anova(modelname, white.adjust="hc3") and receive the error message: "Fehler in SS[i] <- SS.term(names[i]) : nichts zu ersetzen" (German) "Error in SS[i] <- SS.term(names[i]) : nothing to replace" (probably being the

I am trying to get robust standard errors in a logistic regression. Is there any way to do it, either in car or in MASS? Thanks for the help, Celso [[alternative HTML version deleted]]

Hi all, I'm moving to a Mac platform and have installed R and all seems fine. My question concerns moving my R objects over. On my pc, which file contains my R objects and once I copy that, where do I copy it within the Mac? I hope that was clear. Thanks in advance, David -- =============================================================== David Kaplan, Ph.D. Professor

Hi all, I'm running the program sem on a Mac, but I'm getting a message that I think is quite general. The error reads Error in scan(file, what, nmax, sep, dec, quote, skip, nlines, na.strings, : scan() expected 'a real', got '10652)' The 10652 is the sample size coming from a .csv file where I have header = TRUE. Any thoughts would be

Let me try to be more specific. The x y coordinates are different because of NAs in the dataset. In this analysis, a set of hat values (a measure of influence in regression) is given for each observation. On the basis of the regression that was run to get these hat values, the sample size was 1164 (one removed due to NA). The length of the data set is 1165. If I remove the NA from the

Hello, I have just recently started using R and was wondering whether anybody had a code written for White's heteroscedasticity correction for standard errors. Also, can anybody share a code for the GARCH(1,1) and GARCH-in-mean models for modelling regression residuals? Thanks a lot in advance, Spyros --------------------------------- [[alternative HTML version

When using function heckit() from package ‘sampleSelection’, is there anyway to make t-tests for the coefficients using robust covariance matrix estimator? By “robust” I mean something like if a had an object ‘lm’ called “reg” and then used: > coeftest(reg, vcov = vcovHC(reg)). I’m asking this because in Stata we could use function heckman and then use vce option “robust”. We could do the

Hello! I would like to know if there are already programmed statistical tests for data under serial dependence, for example, considering the variance inflation factor? Thank you very much Best regards Rosa

Hello there, I have a linear regression model for which I estimated heteroskedasticity-robust (Huber-White) standard errors using the coeftest function in the lmtest-package. Now I would like to inspect the predicted values of the dependent variable for particular groups and include a confidence interval for this prediction. My question: is it possible to estimate confidence intervals for the

Hi all, Does anyone know how to report heteroskedasticity and autocorrelation-consistent standard errors when using the "spm" command in SemiPar package? Suppose the original command is sp1<-spm(y~x1+x2+f(x3), random=~1,group=id) Any suggestion would be greatly appreciated. Thanks, Susan [[alternative HTML version deleted]]

Hi all, My apologies for a very simple question. I just downloaded R 2.6.0. I want to bring in all of the objects from 2.5.0 that I see when I type ls(). I have no idea how to do that. Thanks in advance. David -- ======================================================================= David Kaplan, Ph.D. Professor Department of Educational Psychology University of Wisconsin - Madison

Dear All, I'm trying to use waldtest to test poolability (parameter stability) between two logistic regressions. Because I need to use robust standard errors (using sandwich), I cannot use anova. anova has no problems running the test, but waldtest does, indipendently of specifying vcov or not. waldtest does not appear to see that my models are nested. H0 in my case is the the vector of

Hi all, I'm looking for R packages that estimate multivariate time-series models or vector-autoregression (VAR) time-series models. Thanks David -- =========================================================================== David Kaplan, Ph.D. Professor Department of Educational Psychology University of Wisconsin - Madison Educational Sciences, Room, 1061 1025 W. Johnson Street Madison,

Hi all, I'm looking for a contributed package that can provide a detailed account of missing data patterns and perhaps also provide imputation procedures, such as mean imputation or hot deck imputation and the like. Is there anything out there? Thanks in advance, David -- =========================================================================== David Kaplan, Ph.D. Professor

Hi, I have been searching and can't seem to find a simple command that will allow me to sample from a multivariate normal distribution with known covariance matrix. I am likely missing something. Thanks in advance. David -- =========================================================================== David Kaplan, Ph.D. Professor Department of Educational Psychology University of