x <- D[,1:2]
is a data.frame!
try this:
D <- data.frame(x1=1:3, x2=c(1,6,10), y=c(10,6,7)) # your data.frame
D. <- data.matrix(D)
x <- D.[,1:2]
y <- D.[,3]
simple1 <- function(xdata, ydata){
ofit <- substitute(lm(ydata~xdata))
list(eval.parent(ofit))
}
##################
simple1(xdata=x, ydata=y)
I hope it helps.
Best, Dimitris
---- Dimitris Rizopoulos Ph.D. Student Biostatistical Centre School of Public Health Catholic University of Leuven
Address: Kapucijnenvoer 35, Leuven, Belgium Tel: +32/16/336899 Fax: +32/16/337015 Web: http://www.med.kuleuven.ac.be/biostat/ http://www.student.kuleuven.ac.be/~m0390867/dimitris.htm
----- Original Message ----- From: "Clark Allan" <[EMAIL PROTECTED]>
To: "Dimitris Rizopoulos" <[EMAIL PROTECTED]>
Cc: <r-help@stat.math.ethz.ch>
Sent: Thursday, February 24, 2005 1:46 PM
Subject: Re: [R] r: functions
hi
i still get the same error. i must be doing something wrong. i have typed in all of the steps i used.
D x1 x2 y 1 1 1 10 2 2 6 6 3 3 10 7
x<-D[,1:2] y<-D[,3]
xx1 x2 1 1 1 2 2 6 3 3 10
y[1] 10 6 7
simple1 <- function(xdata, ydata){+ ofit <- substitute(lm(ydata~xdata)) + list(eval.parent(ofit)) + }
simple1(xdata=x, ydata=y) Error in model.frame(formula, rownames, variables, varnames, extras, extranames, : invalid variable type
I STILL GET THE ERROR. WHAT AM I DOING WRONG?
Dimitris Rizopoulos wrote:
There was a similar question about one week ago regarding the use of
"table(x,y)". One approach could be to use the following:
simple1 <- function(xdata, ydata){ ofit <- substitute(lm(ydata~xdata)) list(eval.parent(ofit)) } ############# simple1(xdata=x, ydata=y) lm(y~x)
I hope it helps.
Best, Dimitris
---- Dimitris Rizopoulos Ph.D. Student Biostatistical Centre School of Public Health Catholic University of Leuven
Address: Kapucijnenvoer 35, Leuven, Belgium Tel: +32/16/336899 Fax: +32/16/337015 Web: http://www.med.kuleuven.ac.be/biostat/ http://www.student.kuleuven.ac.be/~m0390867/dimitris.htm
----- Original Message ----- From: "Clark Allan" <[EMAIL PROTECTED]> To: <r-help@stat.math.ethz.ch> Sent: Thursday, February 24, 2005 10:16 AM Subject: [R] r: functions
> hi all
>
>
> i have a function that uses two inputs, say xdata and ydata. An
> example
> is the following,
>
> simple1<-function(xdata,ydata)
> {
> ofit<-lm(ydata~xdata)
> list(ofit)
> }
>
> say i use arbitray number for xdata and ydata such that
>
> D =
> x1 x2 y
> 1 1 10
> 2 6 6
> 3 10 7
>
>
> x<-D[,1:2]
>
> and
>
> y<-D[,3]
>
> if one uses these inputs and rund the program we get the > following:
>
>>simple(xdata=x,ydata=y)
> Error in model.frame(formula, rownames, variables, varnames, > extras,
> extranames, :
> invalid variable type
>
> why does this happen!
>
> i can get results if i change the program as follows:
>
> simple2<-function(xdata,ydata)
> {
> ofit<-lm(as.matrix(ydata)~as.matrix(xdata))
> list(ofit)
> }
>
> but then the variable names, if they exist, are not preserved. > how
> can i
> preserve these names.
>
> the results are now:
>
>> simple2(xdata=x,ydata=y)
> [[1]]
>
> Call:
> lm(formula = as.matrix(ydata) ~ as.matrix(xdata))
>
> Coefficients:
> (Intercept) as.matrix(xdata)x1 as.matrix(xdata)x2
> -6 21 -5
>
> i've tried converting xdata and ydata to data frames but i still > get
> errors.
>
> simple3<-function(xdata,ydata)
> {
> xdata<-as.data.frame(xdata)
> ydata<-as.data.frame(ydata)
> ofit<-lm(ydata~xdata)
> list(ofit)
> }
>
> i.e.
>
>> simple3(xdata=x,ydata=y)
> Error in model.frame(formula, rownames, variables, varnames, > extras,
> extranames, :
> invalid variable type
>
> please help!
>
> thanking you in advance
>
> ***
> allan
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