Displaying 5 results from an estimated 5 matches for "subset_row4".
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subset_row
2018 Jun 08
4
Subsetting the "ROW"s of an object
...gt;>
>>
>> AFAICS, it is not an issue. Taking
>>
>> arr <- array(rnorm(2^22),c(2^10,4,4,4))
>>
>> as a test case
>>
>> and using a function that will either use the literal code `x[i,,,,drop=FALSE]' or `eval(mc)':
>>
>> subset_ROW4 <-
>> function(x, i, useLiteral=FALSE)
>> {
>> literal <- quote(x[i,,,,drop=FALSE])
>> mc <- quote(x[i])
>> nd <- max(1L, length(dim(x)))
>> mc[seq(4,length=nd-1L)] <- rep(TRUE, nd-1L)
>> mc[["drop"]] <- FALSE...
2018 Jun 08
3
Subsetting the "ROW"s of an object
...recycled. (Maybe there is, or could be, ALTREP, support for
>> recycling)
>> Hadley
AFAICS, it is not an issue. Taking
arr <- array(rnorm(2^22),c(2^10,4,4,4))
as a test case
and using a function that will either use the literal code `x[i,,,,drop=FALSE]' or `eval(mc)':
subset_ROW4 <-
function(x, i, useLiteral=FALSE)
{
literal <- quote(x[i,,,,drop=FALSE])
mc <- quote(x[i])
nd <- max(1L, length(dim(x)))
mc[seq(4,length=nd-1L)] <- rep(TRUE, nd-1L)
mc[["drop"]] <- FALSE
if (useLiteral)
eval(literal)
else...
2018 Jun 08
0
Subsetting the "ROW"s of an object
...AFAICS, it is not an issue. Taking
>>>
>>> arr <- array(rnorm(2^22),c(2^10,4,4,4))
>>>
>>> as a test case
>>>
>>> and using a function that will either use the literal code `x[i,,,,drop=FALSE]' or `eval(mc)':
>>>
>>> subset_ROW4 <-
>>> function(x, i, useLiteral=FALSE)
>>> {
>>> literal <- quote(x[i,,,,drop=FALSE])
>>> mc <- quote(x[i])
>>> nd <- max(1L, length(dim(x)))
>>> mc[seq(4,length=nd-1L)] <- rep(TRUE, nd-1L)
>>> mc[[&qu...
2018 Jun 08
0
Subsetting the "ROW"s of an object
...for
>>> recycling)
>>> Hadley
>
>
> AFAICS, it is not an issue. Taking
>
> arr <- array(rnorm(2^22),c(2^10,4,4,4))
>
> as a test case
>
> and using a function that will either use the literal code `x[i,,,,drop=FALSE]' or `eval(mc)':
>
> subset_ROW4 <-
> function(x, i, useLiteral=FALSE)
> {
> literal <- quote(x[i,,,,drop=FALSE])
> mc <- quote(x[i])
> nd <- max(1L, length(dim(x)))
> mc[seq(4,length=nd-1L)] <- rep(TRUE, nd-1L)
> mc[["drop"]] <- FALSE
> if (useLitera...
2018 Jun 08
2
Subsetting the "ROW"s of an object
I suspect this will have suboptimal performance since the TRUEs will
get recycled. (Maybe there is, or could be, ALTREP, support for
recycling)
Hadley
On Fri, Jun 8, 2018 at 10:16 AM, Berry, Charles <ccberry at ucsd.edu> wrote:
>
>
>> On Jun 8, 2018, at 8:45 AM, Hadley Wickham <h.wickham at gmail.com> wrote:
>>
>> Hi all,
>>
>> Is there a better to