R help - Feb 2004 - return value in function

suppose I have a function example:
 
getMatrix <- function(a,b){
 
     A1<-diag(1,2,2)
 
}
 
If I want to get the both the A1 and dim(A1) from the function, Can I do 
 
return(A1,dim(A1)) inside the function ? And how can I access A1 and dim(A1)
later on?
 
     


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	[[alternative HTML version deleted]]

> suppose I have a function example:
>
> getMatrix <- function(a,b){
>
>      A1<-diag(1,2,2)
>
> }
>
> If I want to get the both the A1 and dim(A1) from the function, Can I do
>
> return(A1,dim(A1)) inside the function ? And how can I access A1 and
> dim(A1) later on?
The general approach for this is to use a list

getMatrix <- function(a,b){
    A1<-diag(1,2,2)
    list(diag=A1,dim=dim(A1))
}

foo <- getMatrix(something)
foo$diag
foo$dim

Cheers

Jason

In general, one would use a list to wrap all objects to be returned into one
object; e.g.,

getMatrix <- function(a, b) {
    A1 <- diag(1,2,2)
    return(list(matrix=A1, dim=dim(A1)))
}

You can then access them as:

mat <- getMatrix(1,1)
mat$matrix
mat$dim

My question is, why do you need to return the dim of the matrix?  The
dimension is already stored in the matrix object as an attribute.  Why store
it yet again?

Andy
> From: li xian
> 
> suppose I have a function example:
>  
> getMatrix <- function(a,b){
>  
>      A1<-diag(1,2,2)
>  
> }
>  
> If I want to get the both the A1 and dim(A1) from the 
> function, Can I do 
>  
> return(A1,dim(A1)) inside the function ? And how can I access 
> A1 and dim(A1) later on? 
>  
>      
> 
> 
> ---------------------------------
> 
> 
> 	[[alternative HTML version deleted]]
> 
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