I did think of this solution, Keith, but I am generally uncomfortable (may be "paranoid" is a better word) with the use of `<<-'. Perhaps, my fear is unjustified in this particular situation.
Thanks, Ravi. ------------------------------------------------------- Ravi Varadhan, Ph.D. Assistant Professor, Division of Geriatric Medicine and Gerontology School of Medicine Johns Hopkins University Ph. (410) 502-2619 email: rvarad...@jhmi.edu -----Original Message----- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of Keith Jewell Sent: Friday, June 24, 2011 11:49 AM To: r-h...@stat.math.ethz.ch Subject: Re: [R] How to capture console output in a numeric format If you don't want the information as character, why are you printing it rather than storing it in a matrix? Why not something along the lines of this... fr <- function(x) { ## Rosenbrock Banana function on.exit(aMatrix <<- rbind(aMatrix,(cbind(x1, x2, f)))) x1 <- x[1] x2 <- x[2] f <- 100 * (x2 - x1 * x1)^2 + (1 - x1)^2 f } aMatrix <- NULL ans <- optim(c(-1.2,1), fr) aMatrix HTH Keith J -----Original Message----- "Ravi Varadhan" <rvarad...@jhmi.edu> wrote in message news:2f9ea67ef9ae1c48a147cb41be2e15c303e...@dom-eb-mail1.win.ad.jhu.edu... Thank you very much, Jim. That works! I did know that I could process the character strings using regex, but was also wondering if there was a direct way to get this. Suppose, in the current example I would like to obtain a 3-column matrix that contains the parameters and the function value: fr <- function(x) { ## Rosenbrock Banana function on.exit(print(cbind(x1, x2, f))) x1 <- x[1] x2 <- x[2] f <- 100 * (x2 - x1 * x1)^2 + (1 - x1)^2 f } fvals <- capture.output(ans <- optim(c(-1.2,1), fr)) Now, I need to tweak your solution to get the 3-column matrix. It would be nice, if there was a more direct way to get the numerical output, perhaps a numeric option in capture.output(). Best, Ravi. ------------------------------------------------------- Ravi Varadhan, Ph.D. Assistant Professor, Division of Geriatric Medicine and Gerontology School of Medicine Johns Hopkins University Ph. (410) 502-2619 email: rvarad...@jhmi.edu ______________________________________________ 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. ______________________________________________ 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.
