Dear R-users I'm running a maximum likelihood procedure using the spg package. I'd like to save some output produced in each iteration to a file, but if I put the capture.output() within the function I get the following message; Error in spg(par = startval, fn = loglik, gr = NULL, method = 3, lower = lo, : Failure in initial function evaluation!Error in -fn(par, ...) : invalid argument to unary operator
I have considered putting the capture.output() after the function, but there are some issues with R stalling on me so I'd like that the output is saved for each iteration and not only at completion. Any suggestions on how to get this done would be much appreciated. Kristian Lind *Below an example of what I'm trying to do...* loglik <- function(w){ state <- c( b_1 = 0, b_2 = 0, a = 0) #declaring ODEs Kristian <-function(t, state, w){ with(as.list(c(state, w)), { db_1 = -((w[1]+w[8])*b_1+(w[2]+w[6]*w[8] +w[7]*w[9])*b_2+0.5*(b_1)^2+w[6]*b_1*b_2+0.5* ((w[6])^2+(w[7])^2)*(b_2)^2) db_2 = -w[3]*b_2+1 da = w[1]*w[4]*b_1+(w[2]*w[4]+w[3]*w[5])*b_2 list(c(db_1, db_2, da)) }) } # time making a sequence from t to T evaluated at each delta seq(t, T, by = delta) times <- seq(0, 10, by = 0.5) outmat <- ode(y = state, times = times, func = Kristian, parms = w) print(w) print(outmat) . . . f<-rep(NA, 1) f[1] <- 1/(T-1)*sum(log(pJ$p)-log(pJ$J)) f capture.output(outmat, file = "spgoutput.txt", append = TRUE) } fit <- spg(fn =loglik, ...) [[alternative HTML version deleted]] ______________________________________________ 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.