R help - Nov 2004 - glim in R?

After some futile searches, I decided to ask the list to see 
if any of the sages out there would have an answer:

I have a function I wrote a few years ago in S, which calls 
glim numerous times.  I'd like to port it to R, but glm 
works differently from glim, which takes as part of its 
input an X design matrix.  I probably could write a function 
to convert glim to glm, but hope this wouldn't be 
necessary...

Tim Liao

Tim F Liao wrote:
> After some futile searches, I decided to ask the list to see 
> if any of the sages out there would have an answer:
> 
> I have a function I wrote a few years ago in S, which calls 
> glim numerous times.  I'd like to port it to R, but glm 
> works differently from glim, which takes as part of its 
> input an X design matrix.  I probably could write a function 
> to convert glim to glm, but hope this wouldn't be 
> necessary...
> 
> Tim Liao
> 
Would glm.fit do what you need? It has much less overhead than glm and 
takes a matrix as it's first argument.

--sundar

Tim Liao wrote:
> After some futile searches, I decided to ask the list to see if any
> of the sages out there would have an answer:
> 
> I have a function I wrote a few years ago in S, which calls glim
> numerous times.  I'd like to port it to R, but glm works differently
> from glim, which takes as part of its input an X design matrix.  I
> probably could write a function to convert glim to glm, but hope this
> wouldn't be necessary...
I doubt that you will get any joy in locating a glim() function for
R.  No-one would write one; that would be wheel-re-invention given the
existence of glm().

The glim() function is antiquated and is or should be deprecated.
The technology has moved beyond that.  What you really should do is
re-write your code to call glm().

If it is ***really*** necessary to pass the design matrix, you should
be able to

	o convert that matrix to a data frame, say ``ddd''
	o call glm(formula,data=ddd)
	o the formula would presumably be simply something
	  like ``y ~ .'' since the predictors would simply
	  be all of the individual columns of your data frame.

I can't see this as being particularly difficult recoding.  Or if you
insist, you could do just create your glim() function as:

	glim <- function(y,X,...) {
		X <- as.data.frame(X)
		glm(y~.,data=X,...)
	}

(I can't really remember the glim syntax, but ``glim(y,X,...)'' is
a reasonable facsimile.)

If your design matrix has a constant column you would want to strip
it out before passing the matrix to you glim() function.

				cheers,

					Rolf Turner
					rolf at math.unb.ca

Great suggestions, and it looks like either suggestion 
should work, although the output from glm may not conform to 
those from glim, thus some more code there perhaps.

Many thanks,

Tim

---- Original message ----
>Date: Mon, 15 Nov 2004 14:28:50 -0400 (AST)
>From: Rolf Turner <rolf at math.unb.ca>  
>Subject: Re: [R] glim in R?  
>To: tfliao at uiuc.edu
>Cc: r-help at stat.math.ethz.ch
>
>Tim Liao wrote:
>
>> After some futile searches, I decided to ask the list to 
see if any
>> of the sages out there would have an answer:
>> 
>> I have a function I wrote a few years ago in S, which 
calls glim
>> numerous times.  I'd like to port it to R, but glm works 
differently
>> from glim, which takes as part of its input an X design 
matrix.  I
>> probably could write a function to convert glim to glm, 
but hope this
>> wouldn't be necessary...
>
>I doubt that you will get any joy in locating a glim() 
function for
>R.  No-one would write one; that would be wheel-re-
invention given the
>existence of glm().
>
>The glim() function is antiquated and is or should be 
deprecated.
>The technology has moved beyond that.  What you really 
should do is
>re-write your code to call glm().
>
>If it is ***really*** necessary to pass the design matrix, 
you should
>be able to
>
>	o convert that matrix to a data frame, say ``ddd''
>	o call glm(formula,data=ddd)
>	o the formula would presumably be simply something
>	  like ``y ~ .'' since the predictors would simply
>	  be all of the individual columns of your data 
frame.
>
>I can't see this as being particularly difficult recoding.  
Or if you
>insist, you could do just create your glim() function as:
>
>	glim <- function(y,X,...) {
>		X <- as.data.frame(X)
>		glm(y~.,data=X,...)
>	}
>
>(I can't really remember the glim syntax, but ``glim
(y,X,...)'' is
>a reasonable facsimile.)
>
>If your design matrix has a constant column you would want 
to strip
>it out before passing the matrix to you glim() function.
>
>				cheers,
>
>					Rolf Turner
>					rolf at math.unb.ca