[R] faster way to use filter this

[David Winsemius]

> On 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)

 c(cost,0)[ match(index, data, nomatch = length(index)+1) ]
#[1]  50 100   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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David Winsemius
Alameda, CA, USA