[R] formula and lm

[solares@unsl.edu.ar]

Hi, don' t understand why the function fomula have this error, i enclose
the parameter "a" with the function I()
Thank Ruben
 x<-1:5
y<-c(  2  ,4 , 6 , 8 ,11)
formu<-y~I(a*x)
form<-formula(formu)
dummy<-data.frame(x=x,y=y)
fm<-lm(form,data=dummy)
Error in unique(c("AsIs", oldClass(x))) : Object "a" not found