[R] package dependency tree

[Prof Brian Ripley]

On Tue, 2 Jan 2007, roger koenker wrote:

> Is there a painless way to find the names of all packages on CRAN
> that "Depend" on a specified package?

Assuming you have just CRAN in your selected repositories:

> foo <- available.packages()
> deps <- strsplit(foo[, "Depends"], ",[[:space:]]*")
> names(deps)[sapply(deps, function(x) "quantreg" %in% x)]
[1] "cobs"    "emplik"  "lss"     "pheno"   "rankreg" "rqmcmb2"

seems painless enough.

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595