[R] list subsets & passing parameters question.

Thomas W Blackwell tblackw at umich.edu
Fri Sep 19 15:27:31 CEST 2003

Eryk  -

Question 1:  Square brackets work, just the same as for
vectors, and return a (smaller or larger) list object.
The new thing with lists, not available (or needed) with
vectors, is double square brackets, which return one list
element as itself, not enclosed in a list.
See  help("Subscript").

Question 2:  No, I don't think there's a way to pass a
whole string of parameters without some kind of complicated
 eval(parse(...)) syntax (which I've never tried to use myself).

I will comment that the REASON I have never tried to use
this is that I am running R inside of emacs, so it's much
easier to edit the buffer and modify and re-run a command
than it would be to figure out some fancy syntactic way of
doing it.

-  tom blackwell  -  u michigan medical school  -  ann arbor  -

On Fri, 19 Sep 2003, Wolski wrote:

> Hi!
> Is there a way to get a subset of a list?
> I looking for some function like the function available for arrays and dataframe.
> x<-1:10
> x[-c(1,2)] for arrays
> or
> x<-data.frame(a=1,b=2)
> subset(x,select=-a)
> But one for a list
> x<-list(a=1,a=2)
> subset(x,select=-a)
> The second problem i have are that i want to store parmeters to the plot.default function in a list. eg.: pars<-list(xlim=c(0,100),xlab="irrelevant" , ylab="incredible important").
> and call the plot.default function with this list as parameters.
> I know that there are the way with eval(parse(text = paste("plot.default",........
> Is there a different one?
> Eryk
> Dipl. bio-chem. Eryk Witold Wolski    @    MPI-MG Dep. Vertebrate Genomics
> Ihnestrasse 73 14195 Berlin          'v'
> tel: 0049-30-84131285               /   \
> mail: wolski at molgen.mpg.de        ---W-W----

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