CODEWITHSUNDEEP
r
EpiMan
EpiMan

Reputation: 839

partial matching in R, charmatch pmatch are not available

I was wondering how it is possible to do partial matching in R?

I wanted to do partial matching to order file names in a list based on another vector like order. order and filenames have a feature in common!

files:
gh456_rr
FFF432
tw4522

order <- c("432","522","456")

    files <- list.files()

    files <- files[ pmatch(order, files) ]

but charmatch pmatch are not available even for R version below 2.10!!

Upvotes: 0

Views: 609

Answers (1)

lawyeR
lawyeR

Reputation: 7654

The problem appears to me to be the mixture characters and digits. I am running the current version of R and tried these variations:

> charmatch(c("gh456_rr", "FFF432", "tw4522"), order <- c("432","522","456"))
[1] NA NA NA
> charmatch(c("", "a432", "a123"), c("1", "123", "432")) # no matches because of letter preceding number
[1]  0 NA NA
> charmatch(c("", "432a", "a123"), c("1", "123", "432")) # same because of letter following
[1]  0 NA NA
> charmatch(c("", "432", "a123"), c("1", "123", "432")) # matches second element "432" to third element "432"
[1]  0  3 NA
> pmatch(c("456_rr", "432", "522"), order <- c("432","522","456")) # doesn't match the first element
[1] NA  1  2
> pmatch(c("456_rr", "432a", "522"), order <- c("432","522","456")) # mixtures of digits and chars doesn't match
[1] NA NA  2
> pmatch(c("gh456_rr", "432a", "t522"), order <- c("432","522","456")) # mixtures of digits and chars doesn't match
[1] NA NA NA

Have you tried agrep()?

Upvotes: 1

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