[R] The equivalent of which() when accessing slots in an object

[Bert Gunter]

But if all the OP want is a count, wouldn't

sum(sapply(buylist, slot, "reqstock") > 100)

suffice?

-- Bert

Bert Gunter

"The trouble with having an open mind is that people keep coming along
and sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )


On Mon, Oct 31, 2016 at 7:31 AM, Bob Rudis <bob at rud.is> wrote:
>     which(purrr::map_dbl(buylist, slot, "reqstock") > 100)
>
> or
>
>     which(sapply(buylist, slot, "reqstock") > 100)
>
> ought to do the trick.
>
> On Mon, Oct 31, 2016 at 10:09 AM, Thomas Chesney
> <Thomas.Chesney at nottingham.ac.uk> wrote:
>> I have the following object
>>
>> setClass("buyer",
>> representation(
>> reqstock="numeric",
>> buyout="numeric"),
>> )
>>
>> nBuy <- 5
>>
>> #Set buyer parameters here
>> buylist <- list()
>> for (i in 1:nBuy){
>> buylist[[i]] <- new("buyer")
>> buylist[[i]]@reqstock <- sample(c(50:200),1)
>> }
>>
>> and want to count the number of objects in buylist that have reqstock greater than 100. Something like this if it was a vector:
>>
>> length(which(buylist[[]]@reqstock > 100))
>>
>> How could I do this please and where could I find more information about manipulating slots? When I try to search for this I just keep finding info on ls() and similar functions.
>>
>> Thank you
>>
>> Thomas Chesney
>> http://www.nottingham.ac.uk/~liztc/Personal/index.html
>>
>>
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>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
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> and provide commented, minimal, self-contained, reproducible code.