e language functions and
are found via the global environment at compile time may be inlined."
This is an area where a small change to the language spec would impact
essentially no users and would result in a language that could be
executed much more efficiently.
Justin Talbot
___
artpl.R is used anywhere, so this may have
never caused an issue. But it's tripping up my R compiler.
Thanks,
Justin Talbot
__
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
The pmatch help (see also section 4.3.2 in the R Language Definition)
claims that pmatch with duplicates.ok=FALSE provides the same
functionality as R's argument matching algorithm, modulo how empty
strings are matched.
Here's an undocumented inconsistency between pmatch and R's argument
matching
In R version 2.15.2 (2012-10-26) i386-apple-darwin9.8.0/i386 (32-bit) I get
the following:
> a <- list(1)
> (a[[1]] <- a)
[[1]]
[[1]][[1]]
[1] 1
but
> a <- list(1)
> b <- a
> (a[[1]] <- a)
[[1]]
[1] 1
And similarly:
> a <- list(x=1)
> (a$x <- a)
$x
$x$x
[1] 1
but
> a <- list(x=1)
> b <- a
>
>
> Then the case for psum is more for convenience and speed -vs-
> colSums(rbind(x,y), na.rm=TRUE)), since rbind will copy x and y into a new
> matrix. The case for pprod is similar, plus colProds doesn't exist.
>
Right, and consistency; for what that's worth.
>> Thus, + should have the signatur
> Because that's inconsistent with pmin and pmax when two NAs are summed.
>
> x = c(1,3,NA,NA,5)
> y = c(2,NA,4,NA,1)
> colSums(rbind(x, y), na.rm = TRUE)
> [1] 3 3 4 0 6# actual
> [1] 3 3 4 NA 6 # desired
But your desired result would be inconsistent with sum:
sum(NA,NA,na.rm=TRUE)
[1] 0
>
>
> Thanks for the clarification Justin. What about the S4 classes
> and methods? The design resembles CLOS, and currently this
> is interpreted R code. Have you addressed performance issues
> associated with this? What relative impact does this have compared
> with other optimizations like vectori
>
> Isn't R much like Lisp under the covers? Afterall, it evolved from Scheme.
> Hasn't there been a great deal of work done on optimizing Lisp over the
> last 30 years? This suggests that instead of dropping the R/S semantics
> and moving to another language like Julia, the proposals of Ross Ihaka
>
> On 8 March 2012 at 11:06, Justin Talbot wrote:
> | I've been working on an R performance academic project for the last
> | couple years which has involved writing an interpreter for R from
> | scratch and a JIT for R vector operations.
>
> Cool. I think John mentio
I've been working on an R performance academic project for the last
couple years which has involved writing an interpreter for R from
scratch and a JIT for R vector operations.
With the recent comments on Julia, I thought I'd share some thoughts
from my experience since they differ substantially f
", but doesn't say anything about evaluation
order.
In general, for primitive and internal functions, is a particular
evaluation order for the arguments guaranteed?
Thanks,
Justin Talbot
__
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
11 matches
Mail list logo