Good morning to all, I am encountering a blocking issue when using the function 'breackpoints' from package 'strucchange'.
*Context:* I use a data frame, 248 observations of 5 variables, no NA. I compute a linear model, as y~x1+...+x4 x4 is a dummy variable (0 or 1). I want to check this model for structural changes. *Process & issues:* *First, I used function Fstats.* It works perfectly. However, this test is not adapted because regression residuals are not independant. That is why *I used 'breackpoints', which works for depedant errors* (Bai, 1997). Syntax: struc.test <- breakpoints(y~x1+x2+x3+x3+x4, data=D) *I get an error message:* Erreur dans chol2inv(qr.R(fm$qr)) : l'élément (5, 5) est nul, donc l'inverse ne peut être calculé (sorry for the french version, I don't know how to get the message english translation in R). My first assumption was this has *something to do with the dummy variable, so I skipped it*: struc.test <- breakpoints(y~x1+x2+x3+x3, data=D) *New error message:* Erreur dans if (max(abs((betar - fm$coefficients)/fm$coefficients)) < tol) check <- FALSE : valeur manquante là où TRUE / FALSE est requis I really can't understand what is going wrong. What 'tol' stands for? Seems it is not a 'breackpoints' attributes. Any help would greatly appreciated. Many thanks in advance, Regards, Michel [[alternative HTML version deleted]]
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