Hello expeRts, I need generate symbolize the autocovariances matrix of a Gaussian ARMA(1,1), for derivate it and evaluate. I try this codes, but whitout sucess
vacv<-NULL vacv[1]<-1-2*phi*theta-theta^2 vacv[2]<-(1-phi*theta)*(phi-theta) vacv[3:n]<-acv[2]*(phi^(1:(n-2))) facv<-list() for(i in 1:2) facv[[i]]<-deriv(y~vacv[i],c("phi","theta"),function(phi,theta){}) Erro en deriv.formula(y ~ vacv[i], c("phi", "theta"), function(phi, theta) { : Función '`[`' no está en la tabla de derivadas dfg<-for(n in 1:2) as.formula(sprintf("y~(1 - phi * theta) * (phi - theta)*phi^ %d",n)) dfg y ~ (1 - phi * theta) * (phi - theta) * phi^2 deriv(dfg[[1]],phi) Erro en deriv.default(expr, namevec, function.arg, tag, hessian) : nombres de variable inválidos Give me a help, please. Bernardo. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.