[R] Re: r: functions

[Clark Allan]

hi all

i worked it out. the following code seems to work. thanx for those who
replied to previous questions.


simple1<-function(xdata,ydata)
{
	DATA<-data.frame(ydata,xdata)
        ofit<-summary(lm(ydata~.,data=DATA))
        list(ofit)
}
simple1(x,y)


> simple1(x,y)
[[1]]

Call:
lm(formula = ydata ~ ., data = DATA)

Coefficients:
(Intercept)           x1           x2  
         -6           21           -5



***
allan


Clark Allan wrote:
> 
> 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