Normalize a PubMed Central identifier

Canonicalizes a PMCID to the PMC####### form, accepting "PMC123", "123", or 123.

Usage

normalize_pmcid(x)

Arguments

x

A character or numeric vector of PMCIDs.

Value

A character vector of PMC-prefixed identifiers, NA where none is present.

Examples

normalize_pmcid(c("PMC5334499", "5334499", "pmc 5334499"))
#> [1] "PMC5334499" "PMC5334499" "PMC5334499"