Why not just use rowSums? Ronggui
2009/6/16 Stu @ AGS <s...@agstechnet.com>: > Hello! > > > > I am trying to write a function with vector and data.frame parameters that > uses the sum() function and values from the rows of the data.frame. > > I need to pass this function as a parameter to optim(). > > > > My starting point is: > > observs <- data.frame(y, x1, x2, x3) > > > > Fn <- function(par, observs) { > > sum( (y - (par[1] * (x1 + 1) * x2^(-par[2]) * x3^par[3])^2 ) > > } > > > > y, x1, x2, x3 are all vectors. > > > > I am a bit new to R and I have not been able to find a good description of > how to iterate over rows in a data.frame. > > > > What is a straightforward way to do this? > > What am I missing? > > > > Thanks > > Stu > > > > > [[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. > -- HUANG Ronggui, Wincent PhD Candidate Dept of Public and Social Administration City University of Hong Kong Home page: http://asrr.r-forge.r-project.org/rghuang.html ______________________________________________ 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.