Is this what you want? > Lines <- "cel 3.0 m/s + Z0 367 ohm + eps0 8.9e-12 F/m + " > Constants.DF <- read.table(textConnection(Lines), as.is = TRUE) > Constants <- as.list(Constants.DF[[2]]) > names(Constants) <- Constants.DF[[1]] > for(i in seq_along(Constants)) comment(Constants[[i]]) <- Constants.DF[i, 3] > > # get value > Constants$Z0 [1] 367 > # get comment > comment(Constants$Z0) [1] "ohm" > # add another Constant > Constants$e <- 2.7 > comment(Constants$e) <- "exp"
On Dec 28, 2007 2:33 PM, baptiste Auguié <[EMAIL PROTECTED]> wrote: > Hi, > > I've started my own (first) package, part of which consists in > listing common physical constants (Planck's constant, the speed of > light in vacuum, etc). I'm wondering what would be a good way of > dealing with pairs of value/unit. > > > > constants <- list( cel = 2.99792458e8 , #m/s > > Z0 = 376.730313461, #ohm > > eps0 = 8.854187817e-12,#F/m > > mu0 = 4*pi*1e-7,#N/A^2 > > G = 6.67428e-11 # m^3 kg-1 s-2 > > ) > > > I thought I could include the unit in the names attribute of each > element, as in : > > > names(constants$cel)<- " speed of light in vacuum [m.s^-1]" > > > Writing this for every element is very redundant... Is there any way > to access and set the name of each first level element of the list? > > > namesFirstLevelElements(constants)<- c(" speed of light in vacuum > > [m.s^-1]", > > "impedance of vacuum [some unit]", > > ...) > > > Quite possibly, I'm completely on the wring track; > > - maybe such a package already exists > > - a custom class or structure would be more appropriate? I don't > really know how to deal with classes, though, and I'd like to keep > the access to the constants' values as direct and generic as possible. > > Many thanks in advance, > > baptiste > > _____________________________ > > Baptiste Auguié > > Physics Department > University of Exeter > Stocker Road, > Exeter, Devon, > EX4 4QL, UK > > Phone: +44 1392 264187 > > http://newton.ex.ac.uk/research/emag > http://projects.ex.ac.uk/atto > > ______________________________________________ > 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. > ______________________________________________ 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.