icd (version 2.2)

combine: combine ICD codes

Description

These function implement combination of lists or vectors of codes, while preserving ICD classes. Base R c just drops all user defined classes and casts down to lowest common denominator, e.g. if mixing numbers and characters. No attempt here to catch all possible combinations of feeding in mixed ICD types and other types. Let R do what it normally does, but just try to keep classes of the first item in the list.

Usage

# S3 method for icd9
c(..., warn = FALSE)
# S3 method for icd10
c(..., warn = FALSE)

Arguments

...

elements to combine

warn

single logical value, if TRUE, will give warnings when incompatible types are combined using c

Examples

# NOT RUN {
# throw an error? or assign type according to first argument?
c(as.icd9("E998"), as.icd10("A10"))

# benchmark subsetting to justify using .subset2 (5% faster)
library(microbenchmark)
j <- list(as.icd9cm("E990"), as.icd9cm("10010"))
k <- list(rep(as.icd9cm("E990"), times = 500))
microbenchmark(j[[1]], .subset2(j, 1),
               k[[1]], .subset2(k, 1),
               times = 1e6)

# logical list to vector
a <- list(T,T)
microbenchmark(as.logical(a), c(a, recursive = TRUE), times = 1e6)

# c(..., recursive = TRUE) vs unlist
l = list(c("100", "440", "999"), c("123", "234"))
microbenchmark::microbenchmark(c(l, recursive = TRUE),
                               c(unlist(l)),
                               times = 1e6)
stopifnot(identical(c(l, recursive = TRUE), c(unlist(l))))

# }