R help - Mar 2007 - apply ? function doesnt create object

hello,
i have written a function to extract certain lines from a matrix. the  
result is a matrix with 6 cols, named dynamically according to the  
functions arguments.

the problem is now, that i'm not able to return the resultmatrix for  
further use. the object is not being created.

example from my console:

getans(27,27)
[...]
[189,] 3969  161   27    1    0    1
[190,] 2142   87   27    1    0    1
[191,] 1318   52   27    1    0    1
[192,] 2881  120   27    1    0    1
[193,] 3669  152   27    1    0    1
[194,] 5653  229   27    1    0    1
[195,] 2308   95   27    1    0    2
[196,] 4942  200   27    1    0    1
the matrix ansblock27 contains answers to block 27
 > ansblock27
error: object "ansblock27" not found
 >



the code of the function:

getans = function(x=qids,bnr=1,type="block")
	{
#generate name of matrix
matnam=paste("ans",type,as.character(bnr),sep="")

#display result matrix
show(assign(matnam,matrix(as.numeric(as.matrix(allans[(allans[, 3] %in 
% x), , drop = FALSE])),ncol=dim(allans)[2])))

#create result matrix
assign(matnam,matrix(as.numeric(as.matrix(allans[(allans[, 3] %in%  
x), , drop = FALSE])),ncol=dim(allans)[2]))

#print info
cat("the matrix",matnam,"contains answers
to",type,as.character(bnr))
	
}

i have tried to use "return", but had no success.

what else can i do?

thx in advance, and have a nice weekend
regards,


	[[alternative HTML version deleted]]

On Mar 3, 2007, at 4:28 PM, bunny , lautloscrew.com wrote:

Please use <- for assignments instead of = :
> getans = function(x=qids,bnr=1,type="block")
> 	{
> #generate name of matrix
> matnam=paste("ans",type,as.character(bnr),sep="")
>
> #display result matrix
> show(assign(matnam,matrix(as.numeric(as.matrix(allans[(allans[, 3] %in
> % x), , drop = FALSE])),ncol=dim(allans)[2])))
You are assigning things twice here.
> #create result matrix
> assign(matnam,matrix(as.numeric(as.matrix(allans[(allans[, 3] %in%
> x), , drop = FALSE])),ncol=dim(allans)[2]))
The documentation for assign makes it pretty clear that the  
assignment happens by default in the current environment, so it will  
be local to the function unless you alter the call. The description  
there, along with the examples, and a study of environments, should  
provide you with the answer.
> #print info
> cat("the matrix",matnam,"contains answers
to",type,as.character
> (bnr))		
> 	
> }
Haris Skiadas
Department of Mathematics and Computer Science
Hanover College