search for: g0c7

I ran into strange behavior when removing names. Two ways of removing names: i <- rep(1:4, length.out=20000) k <- c(a=1, b=2, c=3, d=4) x1 <- unname(k[i]) x2 <- k[i] x2 <- unname(x2) Are they identical? identical(x1,x2) # TRUE but no identical(serialize(x1,NULL),serialize(x2,NULL)) # FALSE But problem is with serialization type 3, cause:

Very interesting: > .Internal(inspect(k[i])) @10a4bc000 14 REALSXP g0c7 [ATT] (len=20000, tl=0) 1,2,3,4,1,... ATTRIB: @7fa24f07fa58 02 LISTSXP g0c0 [REF(1)] TAG: @7fa24b803e90 01 SYMSXP g0c0 [MARK,REF(5814),LCK,gp=0x6000] "names" (has value) @10a4e4000 16 STRSXP g0c7 [REF(1)] (len=20000, tl=0) @7fa24ba575c8 09 CHARSXP g0c1 [MARK,REF(35005),gp...

...: x <- seq(1, 100, 1) y <- seq(1, 100, 1) reg_xy <- stats:::regularize.values(x, y, mean) # Regularized versions of `x` and `y` are identical to input but are stored at # different places identical(x, reg_xy[["x"]]) #> [1] TRUE .Internal(inspect(x)) #> @15719b0 14 REALSXP g0c7 [NAM(3)] (len=100, tl=0) 1,2,3,4,5,... .Internal(inspect(reg_xy[["x"]])) #> @2b84130 14 REALSXP g0c7 [NAM(3)] (len=100, tl=0) 1,2,3,4,5,... identical(y, reg_xy[["y"]]) #> [1] TRUE .Internal(inspect(y)) #> @2c91be0 14 REALSXP g0c7 [NAM(3)] (len=100, tl=0) 1,2,3,4,5,......

...: x <- seq(1, 100, 1) y <- seq(1, 100, 1) reg_xy <- stats:::regularize.values(x, y, mean) # Regularized versions of `x` and `y` are identical to input but are stored at # different places identical(x, reg_xy[["x"]]) #> [1] TRUE .Internal(inspect(x)) #> @15719b0 14 REALSXP g0c7 [NAM(3)] (len=100, tl=0) 1,2,3,4,5,... .Internal(inspect(reg_xy[["x"]])) #> @2b84130 14 REALSXP g0c7 [NAM(3)] (len=100, tl=0) 1,2,3,4,5,... identical(y, reg_xy[["y"]]) #> [1] TRUE .Internal(inspect(y)) #> @2c91be0 14 REALSXP g0c7 [NAM(3)] (len=100, tl=0) 1,2,3,4,5,......

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

...However, if I create a vector of length 1024, R will give me a normal real-type vector ``` > x <- 1:1024 > y <- wrap_altrep(x) > .Internal(inspect(y)) @0x000000001f8ddb20 13 INTSXP g0c0 [REF(2)] I am altrep > y[1] <- 1.0 > .Internal(inspect(y)) @0x000000001f0d72a0 14 REALSXP g0c7 [REF(1)] (len=1024, tl=0) 1,2,3,4,5,... ``` Note that the duplicate function is also called for the first example. It seems like R completely ignores my ALTREP functions in the second example. I feel this might be designed on purpose, but I do not understand the reason behind it. Is there any reas...

...references by setting NAMED to 2. You can see this with > e <- new.env(parent = emptyenv()) > e$x <- list(1) > .Internal(inspect(e)) @30b2498 04 ENVSXP g0c0 [NAM(1)] <0x30b2498> ENCLOS: @2600e98 04 ENVSXP g0c0 [MARK,NAM(2)] <R_EmptyEnv> HASHTAB: @2e41540 19 VECSXP g0c7 [] (len=29, tl=1) @25c9628 00 NILSXP g0c0 [MARK,NAM(2)] @25c9628 00 NILSXP g0c0 [MARK,NAM(2)] @25c9628 00 NILSXP g0c0 [MARK,NAM(2)] @25c9628 00 NILSXP g0c0 [MARK,NAM(2)] @30b3370 02 LISTSXP g0c0 [] TAG: @2637870 01 SYMSXP g0c0 [MARK,NAM(2)] "x" @3569...

...al-type vector >> ``` >> > x <- 1:1024 >> > y <- wrap_altrep(x) >> > .Internal(inspect(y)) >> @0x000000001f8ddb20 13 INTSXP g0c0 [REF(2)] I am altrep >> > y[1] <- 1.0 >> > .Internal(inspect(y)) >> @0x000000001f0d72a0 14 REALSXP g0c7 [REF(1)] (len=1024, tl=0) >> 1,2,3,4,5,... >> ``` >> >> Note that the duplicate function is also called for the first example. It >> seems like R completely ignores my ALTREP functions in the second example. >> I feel this might be designed on purpose, but I do n...

...R will give me a normal > real-type vector > ``` > > x <- 1:1024 > > y <- wrap_altrep(x) > > .Internal(inspect(y)) > @0x000000001f8ddb20 13 INTSXP g0c0 [REF(2)] I am altrep > > y[1] <- 1.0 > > .Internal(inspect(y)) > @0x000000001f0d72a0 14 REALSXP g0c7 [REF(1)] (len=1024, tl=0) 1,2,3,4,5,... > ``` > > Note that the duplicate function is also called for the first example. It > seems like R completely ignores my ALTREP functions in the second example. > I feel this might be designed on purpose, but I do not understand the > reason...

Hello, Doing typeof() on an object appears to reset the "named" field in its sxpinfo header to 2, which can change the way that subsequent subassignment operations are carried out: X <- 1:5e7 .Internal(inspect(X)) # @4eeb0008 13 INTSXP g0c7 [NAM(1)] (len=50000000, tl=0) 1,2,3,4,5,... system.time(X[1] <- 9L) # user system elapsed # 0 0 0 typeof(X) .Internal(inspect(X)) # @4eeb0008 13 INTSXP g1c7 [MARK,NAM(2)] (len=50000000, tl=0) 9,2,3,4,5,... system.time(X[2] <- 9L) # user system elapsed # 0.16...