summary.lm output customization

Question

I would like my lm summary output to be a little more compact than usual. I want to remove some newlines, the "Residuals" section, the line with the word "Coefficients". on the positive side, summary.lm is written as a native R function, so presumably I can just copy it to a file, change it, and then source it through my .Rprofile. on the negative side, when I try the first step (copy into emacs and source it), it complains that qr.lm is not found. is there magic, or am I missing something?

how do I redefine it?

summary.lm <- function(object, correlation = FALSE, symbolic.cor = FALSE,
      print.residstable = TRUE, succinct = FALSE, ...)

whatever I will get is not ideal. if someone upstream makes a change in summary.lm, I will have to redo my code. still, in the absence of parameters to control the printing verbosity, I don't know how else to do this.

Answer 1

Indeed, redefining summary.lm is the way to go for what you want to do.

What you are missing is the concept of namespace in R. summary.lmis a function from the stats package and so has access to internal functions of this package. Only some functions from a package are exported and available once the package is loaded.

qr.lm is precisely such an internal function. It is accessible with the triple ::: operator (see ?/:::``):

> qr.lm
Error: object 'qr.lm' not found

> stats::qr.lm
Error: 'qr.lm' is not an exported object from 'namespace:stats'

> stats:::qr.lm
function (x, ...) 
{
    if (is.null(r <- x$qr)) 
        stop("lm object does not have a proper 'qr' component.\n Rank zero or should not have used lm(.., qr=FALSE).")
    r
}
<bytecode: 0x0000000017983b68>
<environment: namespace:stats>

As you can see, it simply extracts the qr component of the lm object. You can just paste the code instead of calling the function.