[R] converting to a language object
MSchwartz at medanalytics.com
Sat Feb 8 04:01:03 CET 2003
Arnab mukherji wrote:
> I have a query about the following:
> CONTEXT: if we define:
> eq <- y ~ x1 + x2
> then is.language(eq) returns true. this works perfectly with commands
> such as lm(eq,data=my.data)
> THE PROBLEM: Now I have a big data set with about 2000 independent
> variables. So I tried to automate this. I can pick off the names of
> the variables and insert a plus in between them and get a string.
> Thus I have
> eq<- y ~ " x1 + x2 + ... +x2000" or eq<-"y ~ " x1 + x2 + ... +x2000"
> from either case how can I typecast eq into a langugae object and get
> the lm command to work ?
> Does anyone have any suggestions?
Once you have your full formula string constructed you can use:
eq <- eval(parse(text = string))
This will put the model formula into eq.
For example try:
eq <- eval(parse(text = "y ~ x1 + x2"))
See ?eval and ?parse for more information.
Hope that helps.
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