Hi, I am trying to recursively apply a function to a selection of columns in a dataframe. I've had a look around and from what I have read, I should be using some version of the apply function, but I'm really having some headaches with it.
Let me be more specific with an example. Say I have a data frame similar to the following A x y z r1 r2 r3 r4 0.1 0.2 0.1 ... 0.1 0.3 ... 0.2 ... i.e., a number of columns, each of the same length, and all containing real numbers. Of these columns, I want to model one variable, say A, as a function of other variables, say x, y, z, and any one of my r1, r2, r3, ... variables. i.e., I want to model A ~ x + y + z + r1 A ~ x + y + z + r2 .... A ~ x + y + z + rn But where the number of 'r' variables I will have will be large, and I don't know the specific number of these variables in advance. My question first is, how can I select all the columns in a dataframe that have a heading that matches a string pattern? And then related to this, what would be the best way of repeatedly applying my modelling function to the result? Many thanks for any help for this occasional R armature. Claus ______________________________________________ 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.
