parse on left hand side of R assignment
On Sat, 31 May 2003, Paul E. Johnson wrote:
I keep finding myself in a situation where I want to calculate a
variable name and then use it on the left hand side of an assignment.
For example
iteration <- 1
varName <- paste("run",iteration,sep="")
myList$parse(text=varName) <- aColumn
I want to take some existing variable "aColumn" and use the name
"varName" name for it and put it into a list "myList". That use fails
with this error:
Error: couldn't find function "(<-"
I've tried many variations on the theme.
If I could do this with a data frame, I would be just as happy. Right
now I'm using a list rather than a data frame because not all columns
are of the same length. But I can work around that.
For a data frame you could use
mydf[paste("run",iteration,sep="")] <- aColumn
and for a list or a data frame
Robject[[paste("run",iteration,sep="")]] <- aColumn
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