similar to: Is there way to trace memory in the dtrace ?

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

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 have a problem in understanding what the assignment operator '<-' really is doing. If i create two numeric arrays in R and copy one into the other with '<-' and afterwards change one array by calling a C function, both arrays are changed! The problem I am facing can easily be seen in the following example: (The following R code and the C function is attached and

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] <-

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

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]]

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, $ 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

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

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

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.

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

Hi When I try to update an number in a large data.frame by its pos It's really slow it take almost a sec to do this and I wonder why and if where is any faster way to update a number in a data.frame ive tried DF$col[POS]<-number DF[xPOS,yPOS]<-number Thx //Joel -- View this message in context: http://r.789695.n4.nabble.com/Slow-update-insert-on-Data-frame-tp3055707p3055707.html

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]]

Hi, I haven't found a way to display the memory location of an object in R. Is there one? (I want to see whether some code 'grows' an object, and an ever-changing memory location for the object would presumably confirm this) Thanks m -- View this message in context: http://r.789695.n4.nabble.com/memory-location-of-object-tp3207798p3207798.html Sent from the R help mailing list

I'm looking at memory efficiency for some of the survival code. The following fragment appears in coxph.fit coxfit <- .C("coxfit2", iter=as.integer(maxiter), as.integer(n), as.integer(nvar), stime, sstat, x= x[sorted,] , ... Does this make a second copy of x to pass to the routine (my

Hi, after updating R 2.5.0 devel yesterday we today observed many new unexpected failures in our daily package build and test system runs, which can be traced to recent changes in the implementation in try() (as noted in NEWS). Investigating this new implementation I come across an issue in conjuntion with using S4 classes and methods. try(expr) does not return an object with attribute

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 '[',

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

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