Conversion of strings to expressions
?get
vec<-c(1,2,3,2)
get("vec") == 2
[1] FALSE TRUE FALSE TRUE Note that this is converting a string to an object, not to an expression: the latter is done by
parse(text="vec")
expression(vec)
On Thu, 4 Nov 2004, Alexander Sokol wrote:
I'm not sure how to state my question in a technically accurate manner, so I'll use a short example to clarify my problem: Say I have a vector, vec<-c(1,2,3,2) I would like to be able to "reference" the vector by using the string containing the name of the vector - that is, I would like to know of some function which is able to convert the string "vec" into the vector vec itself. The purpose of this is to be able to do something like
somefunc("vec")==2
[1] FALSE TRUE FALSE TRUE I hope it is clear from this what the problem is. It seems to me that the function desired is akin to a sort of "inverse" to the quote() function, but I have been unable to find such a function. I am using R 1.9.1 on Windows 2000 SP4. Does anyone have a suggestion of how to solve the problem?
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