[R] formula and lm

[Petr Pikal]

Hallo

On 15 Jul 2004 at 13:46, solares at unsl.edu.ar wrote:

> 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

You did not created object "a" before you have done your 
calculations, as the error message clearly states. 

try

a<-5
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)

But if you want to estimate "a" follow previous replies and try to 
read help page for lm(). 

formu<-y~x

is probably what you want :-).

Cheers
Petr

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Petr Pikal
petr.pikal at precheza.cz