similar to: Assignment operator and deep copy for calling C functions

Is putting a variable into a list a deep copy (and is tracemem the correct way to confirm)? warmstrong at krypton:~/dvl/R.packages$ R > x <- rnorm(1000) > tracemem(x) [1] "<0x3214c90>" > x.list <- list(x.in.list=x) tracemem[0x3214c90 -> 0x2af0a20]: > Is it possible to put a variable into a list without causing a deep copy (i.e. if you _really_ want the

My understanding is that R will not make copies of lists if there is only one reference to the object. However, I've encountered a case where R does make copies, even though (I think) there should be only one reference to the object. I hope that someone could shed some light on why this is happening. I'll start with a simple example. Below, x is a list with one element, and changing that

Hi, I've noticed that as.vector() always allocates a new object, e.g. > x <- 1:10; > x <- as.vector(x); > tracemem(x); [1] "<0x0000000005622db8" > x <- as.vector(x); tracemem[0x0000000005622db8 -> 0x0000000005622ec0]: as.vector > x <- as.vector(x); tracemem[0x0000000005622ec0 -> 0x0000000005622f18]: as.vector > x <- as.vector(x);

Hi all, I've been trying to get a better handle on what manipulations lead R to duplicate a vector, creating small experiments and using tracemem to observe what happens (all in 2.15.1). That's lead me to a few questions, illustrated using the snippet below. x <- 1:10 tracemem(x) # [1] "<0x1058f8238>" x[5] <- 5 # tracemem[0x1058f8238 -> 0x105994ab0]: x[11] <-

Hi, $ R --vanilla R version 2.14.1 (2011-12-22) Platform: i686-pc-linux-gnu (32-bit) > DF = data.frame(a=1:3,b=4:6) > DF a b 1 1 4 2 2 5 3 3 6 > tracemem(DF) [1] "<0x8898098>" > names(DF)[2]="B" tracemem[0x8898098 -> 0x8763e18]: tracemem[0x8763e18 -> 0x8766be8]: tracemem[0x8766be8 -> 0x8766b68]: > DF a B 1 1 4 2 2 5 3 3 6 > Are those 3

Hi Expert I want to use dtrace to monitor the content change of one file. I made following scripts, #!/usr/sbin/dtrace -s inline int MYPID = $1; syscall::write:entry /pid == MYPID/ { tracemem(arg1, arg2); printf("\n"); } It always has an following error bash-3.00$ sudo dumpFIFO.dtrace 3836 dtrace: failed to compile script ./dumpFIFO.dtrace: line 19: tracemem( ) argument #2

I was trying to use tracemem to look at mblk contents. First, I tried to use mblk->b_wptr - mblk->b_rptr as the size, and was told that it had to be a constant. Foo. (RFE #1). Then, I tried to use 8 as the size, and kept getting decimal numbers printed. Stumbled on #pragma D option rawbytes=true (is the =true necessary, btw?) and that didn''t help. Then, in desperation, I

N_conreq:entry { self->x=1; calledaddr=(struct xaddrf *)arg3; callingaddr=(struct xaddrf *)arg4; trace(calledaddr->link_id); tracemem(calledaddr->DTE_MAC.lsap_add, 80); trace(callingaddr->link_id); tracemem(callingaddr->DTE_MAC.lsap_add, 80); } 0 -> N_conreq 255

Hello all, A friend recently brought to my attention that vector assignment actually recreates the entire vector on which the assignment is performed. So for example, the code: x[10]<- NA # The original call (short version) Is really doing this: x<- replace(x, list=10, values=NA) # The original call (long version) # assigning a whole new vector to x Which is actually doing this: x<-

Hi all, Where can I find an R binary version (>2.4.0 ) for windows that compiled with R_MEMORY_PROFILING? Within our application we are experiencing serious problems with memory usage. And being able to use "Rprofmem" and "tracemem" command seems like our best option. Thanks, Yoni [[alternative HTML version deleted]]

On Fri, 5 Aug 2016, Winston Chang wrote: > My understanding is that R will not make copies of lists if there is > only one reference to the object. However, I've encountered a case > where R does make copies, even though (I think) there should be only > one reference to the object. I hope that someone could shed some light > on why this is happening. > > I'll start

Dear all I am trying to find the best way to handle large fields in reference classes. As the code below shows assignment via <<- causes many copies to be made if the subsetting is extensive (in modb1). This can cause R to run out of memory. Creating a local copy and using the optimisation in <- is the best solution I have found so far (in modb2) - but it is not really much better than

Hi there, I seek your expert opinion on the following memory related questions. The output below was gotten from R-2.6.2, compiled with --enable-memory-profiling on Ubuntu Linux. ======================================================================= >>> Code and output 1: > gc( ) used (Mb) gc trigger (Mb) max used (Mb) Ncells 131180 7.1 350000 18.7 350000 18.7

I'm interested in playing around with memory profiling in R-devel (as described at http://developer.r-project.org/memory-profiling.html) and was trying to figure out how to compile R-devel so that I can use the 'tracemem()' function. But I can't figure out how/where to set R_MEMORY_PROFILING. Is it on the configure command line? Thanks for any help, -roger -- Roger D. Peng

I've been playing with passing arguments to .C(), and found that replacing as.double(x) with if(is.double(x)) x else as.double(x) saves time and avoids one copy, in the case that x is already double. I suggest modifying as.double to avoid the extra copy and just return x, when x is already double. Similarly for as.integer, etc. [[alternative HTML version deleted]]

OBJECTIVE: To update source(..., print.eval=FALSE) to not use withVisible() unless really needed. This avoids unnecessary increases of reference counts/NAMED introduced by withVisible(), which in turn avoids unnecessary memory allocations and garbage collection overhead. This has an impact on all source():ed scripts, e.g. pre-allocation of large matrices to save memory does *not always* help in

Hi there, Problem :: When one tries to change one or some of the columns of a data.frame, R makes a copy of the whole data.frame using the '*tmp*' mechanism (this does not happen for components of a list, tracemem( ) on R-2.6.2 says so). Suggested solution :: Store the columns of the data.frame as a list inside of an environment slot of an S4 class, and define the '[',

Hello, I would like for my C function to be able to manipulate some values stored in an R data frame. To achieve this, a need the (real) memory address where the R data frame stores its data (hopefully in a contiguous way). Then, from R, I call the C function and passing this memory address as a parameter. The question: how can we get the memory address of the R data frame? Thank you! L.

Hi Lille, Is it possible you're looking for tracemem() or inspect() ? > x <- data.frame(z = 1:10)> tracemem(x)[1] "<0x55aa743e0bc0>" > x[1] <- 2Ltracemem[0x55aa743e0bc0 -> 0x55aa778f6ad0]: tracemem[0x55aa778f6ad0 -> 0x55aa778f6868]: [<-.data.frame [<- tracemem[0x55aa778f6868 -> 0x55aa778f5b48]: [<-.data.frame [<- >

Gabriel Becker writes: AFAIK R does not automatically copy function arguments. R actually tries very hard to avoid copying while maintaining "pass by value" functionality. ... R only copies data when you modify an object, not when you simply pass it to a function. This is a bit misleading. R tries to avoid copying by maintaining a count of how many references there are to an