lille stor,
As a general rule, please do not cross-post.
And almost certainly do not simultaneously as you did here and on
https://stackoverflow.com/questions/59663174/get-memory-address-of-an-r-data-frame
Dirk
--
http://dirk.eddelbuettel.com | @eddelbuettel | e...@debian.org
__
On 1/9/20 06:56, Stepan wrote:
> On 09. 01. 20 15:41, lille stor wrote:
>
>> I believe this could be done without creating side effects (e.g.
>> crash) as we are just talking about changing values.
A crash would certainly be an annoying "side effect" ;-)
As Stepan explained, data.frame objects
On 09. 01. 20 15:41, lille stor wrote:
I believe this could be done without creating side effects (e.g.
crash) as we are just talking about changing values.
that is exactly the issue that my last two points warn about. Example:
a <- mtcars
.Call("my_innocent_function", a)
Would you expect th
On 1/9/20 1:03 PM, Ezra Tucker wrote:
Hi Lille,
Is it possible you're looking for tracemem() or inspect() ?
Please note these functions are only for debugging. They should never be
called from programs or packages. One should never try to manipulate
pointers from R directly or even hold them
Hello Lille,
raw data of a data.frame (or more precisely a list, because data.frame
is just a list with "data.frame" class) is an array of R specific data
structures (SEXP), so a generic C function will not be able to work with
them.
As a per-processing step, you may allocate an array for th
Hi Lille,
To my understanding, there's no need to get the actual memory address of
the R data frame, as using .Call() or .External() can be used in a "call by
reference" way as well. This would be contrary to standard R behaviour, so
if you use that in a package, make sure you indicate this!
Ther
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]:
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
