[R] faster way to use filter this

[Bert Gunter]

You neglected the commas in your index expression!

See ?match

as in:

> out <- cost[match(data,index)]
> out
[1]  50 100  NA

(and "data" is a bad name to use as there is already a data() function in R).

Please DO go through an R tutorial or two to learn about some of these
basic, useful  R capabilities. There are many good ones on the Web.

Cheers,
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 Fri, Apr 15, 2016 at 5:58 PM, Paul Tremblay <paulhtremblay at gmail.com> wrote:
> I have the following (simplified) vectors:
> index <- c("shoe"  "shirt" "fruit")
> cost <- c(100, 50, 2)
> data <- c("shirt", "shoe", "vegetable")
>
> I want my outcome to be:
>
> (50, 100, 0)
>
> (shirt => 50, shoe => 100, vegetable => not found, so 0)
>
> I have written the following function:
>
>
> for (i in custom_list) {
> + this_cost <- cost[index == i]
>
> + message(this_cost)
> + }
>
>
> This gives me (50, 100)
>
> I haven't figured out how to use the ifelse. But more importantly, I think
> there should be an easier, and faster way to do this with vectors?
>
> Thanks!
>
> Paul
>
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>
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