Your problem is that your function log1( , ) is not vectorized with respect to its arguments. For a function to work in outer(...) it must accept vectors for its first two arguments and it must produce a parallel vector of responses.
To quote the help information for outer: "FUN is called with these two extended vectors as arguments. Therefore, it must be a vectorized function (or the name of one), expecting at least two arguments." Sometimes Vectorize can be used to make a non-vectorized function into a vectorized one, but the results are not always entirely satisfactory in my experience. See ?Vectorize Bill Venables CSIRO Laboratories PO Box 120, Cleveland, 4163 AUSTRALIA Office Phone (email preferred): +61 7 3826 7251 Fax (if absolutely necessary): +61 7 3826 7304 Mobile: +61 4 8819 4402 Home Phone: +61 7 3286 7700 mailto:[EMAIL PROTECTED] http://www.cmis.csiro.au/bill.venables/ -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Pete Dorothy Sent: Wednesday, 5 March 2008 3:38 AM To: r-help@r-project.org Subject: [R] vector manipulations Hello, I have simulated a set of data which i called "nir" (a vector). I have created a function "logl" which calculates the log-likelihood. logl is a function of 2 real parameters : "beta" and "zeta" (of length 1). This function works perfectly well when I try for example "logl(0.1,0.2)" Now if I try : x <- seq(0.1, 0.5, by = 0.1) y <- seq(0.1, 0.5, by = 0.1) z <- outer(x, y, logl)" I get an error. The problem seems to be that inside "logl", the following expression is calculated : "sum( log( beta+(nir-1)*zeta ) )". So it is a vector manipulation. The error tells me that "nir" is not the size of "zeta". Yet usually it is no problem since "length(zeta)=1". When I replace "sum( log( beta+(nir-1)*zeta ) )" by a loop, I get no mistake. But I think it slows down the program. Do you have an idea where the problem is ? Thank you very much. [[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. ______________________________________________ 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.
