[Rd] How to force dispatch to an internal generic?

2013-12-20 Thread Skye Bender-deMoll 

Dear R-devel,

I have a class 'myClass' in R that is essentially a list with 
pre-specified structure. It has an assignment operator which is going to 
do some things and then should assign the value using the regular list 
assignment operator


`$<-.myClass`<-function(x,i,value){
   # do some pre-processing  stuff

   # make the assignment using the default list assignment
   x[[i]]<-value
   x
 }

But I can't actually use x[[i]]<-value as it will dispatch to the 
already existing [[<-.myClass method.


In similar S3 dispatching cases, I've been able use UseMethod or 
specifically call [[<-.list, or [[<-.default but those don't seem to 
exist because $<- and [[<- are primitive generics, right?  I couldn't 
figure out a way to effectively call call NextMethod, and I assume 
calling .Primitive("$<-") is not appropriate.


My current solution mirrors $<-.data.frame

`$<-.data.frame` <- function (x, name, value) {
  cl <- oldClass(x)
  class(x) <- NULL
  x[[name]] <- value
  class(x) <- cl
  x
}

but according to tracemem(), this is triggering three deep copies of 
myClass objects (which can be expensive as the object is often very 
large ) with each $ assignment instead of one.


Is there a better way to dispatch the assignment to the default 
assignment method?



Note: I previously posted the same question at
http://stackoverflow.com/questions/20627776/how-to-force-dispatch-to-an-internal-generic-in-r

thanks for your help,
 -skye

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[Rd] Fwd: How to check if R interpreter is initiated

2013-12-20 Thread Sandip Nandi 
Hi R-Developers ,

I am using R-3.1 , moved from R-2.15 . I am facing a problem which I have
raised in R bug report with bug 15596 .

My problem is how to check if R is initiated before initiating R

I am embedding R in parallel environment and reusing process already
running to reduce overhead . Each process is running infinitely. So when a
process is reused,it finds R is already initialized there and throws the
error.

Till 2.15 it was solved using R_Is_running variable . So I am assuming
there should be some flag or return value in R-3.0.2 which provides the
user with information if already initialized .

Anyone has faced the problem ?

It will be great if anyone could suggest alternate solution to this problem
for R-3.0.

Thanks,
Sandy

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Re: [Rd] Fwd: How to check if R interpreter is initiated

2013-12-20 Thread Duncan Murdoch 

On 13-12-20 2:00 PM, Sandip Nandi wrote:

Hi R-Developers ,

I am using R-3.1 , moved from R-2.15 . I am facing a problem which I have
raised in R bug report with bug 15596 .

My problem is how to check if R is initiated before initiating R

I am embedding R in parallel environment and reusing process already
running to reduce overhead . Each process is running infinitely. So when a
process is reused,it finds R is already initialized there and throws the
error.

Till 2.15 it was solved using R_Is_running variable . So I am assuming
there should be some flag or return value in R-3.0.2 which provides the
user with information if already initialized .

Anyone has faced the problem ?

It will be great if anyone could suggest alternate solution to this problem
for R-3.0.


As you've already been told:  just maintain your own variable for this. 
 Before initializing R, set it to 0.  After initializing R, set it to 1.


Duncan Murdoch

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