For the column names of the result of expand.grid(), I would just assign them the values I wanted, like this:
> x <- expand.grid(tmp=1:3,y=1:2) > x tmp y 1 1 1 2 2 1 3 3 1 4 1 2 5 2 2 6 3 2 > colnames(x)[1] <- "whatever" > x whatever y 1 1 1 2 2 1 3 3 1 4 1 2 5 2 2 6 3 2 > -- Tony Plate D. R. Evans wrote: > D. R. Evans said the following at 09/04/2007 04:14 PM : >> I am 100% certain that there is an easy way to do this, but after > > I have reconsidered this and now believe it to be essentially impossible > (or at the very least remarkably difficult) although I don't understand why > it is so :-( > > At least, I spent another two hours trying variations on the suggestions I > received, but still nothing worked properly. > > It sure seems like it _ought_ to be easy, because of the following argument: > > If I type an expression such as "A <- <something>" then R is perfectly > capable of parsing the <something> and executing it and assigning the > result to A. So it seems to follow that it ought to be able to parse a > string that contains exactly the same sequence of characters (after all, > why should the R parsing engine care whether the input string comes from > the terminal or from a variable?) and therefore it should be possible to > assign "<something>" to a variable and then have R parse that variable > precisely as if it had been typed. > > That was my logic as to why this ought to be easy, anyway. (And there was > the subsidiary argument that this is easy in the other languages I use, but > R is sufficiently different that I'm not certain that that argument carries > much force.) > > It does seem that there are several ways to make the > > lo <- loess(percent ~ ncms * ds, d, control=loess.control(trace.hat = >> 'approximate')) > > command work OK if the right hand side is in a character variable, but I > haven't been able to find a way to make > > grid <- data.frame(expand.grid(ds=MINVAL:MAXVAL, ncms=MINCMS:MAXCMS)) > > work. > > I always end up with a parse error or a complaint that "'newdata' does not > contain the variables needed" when I perform the next task: > > plo <- predict(lo, grid). > > So I guess I have to stick with half a dozen compound "if" statements, all > of which do essentially the same thing :-( > > ______________________________________________ > R-help@stat.math.ethz.ch 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@stat.math.ethz.ch 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.
