The R package wrapr 1.5.0 is now available on CRAN.

wrapr includes a lot of tools for writing better R code:

• let() (let block)
• %.>% (dot arrow pipe)
• build_frame() / draw_frame() ( data.frame builders and formatters )
• qc() (quoting concatenate)
• := (named map builder)
• %?% (coalesce) NEW!
• %.|% (reduce/expand args) NEW!
• uniques() (safe unique() replacement) NEW!
• partition_tables() / execute_parallel() NEW!
• DebugFnW() (function debug wrappers)
• λ() (anonymous function builder)

I’ll be writing articles on a number of the new capabilities. For now I just leave you with the nifty operator coalesce notation.

Coalesce takes values from its arguments in left to right order taking the first non-NA value (if any available):

NA %?% 5 
# [1] 5

1 %?% 5 
# [1] 1

5 %?% NA
# [1] 5

For vectors each position is calculated independently, and scalars are re-cycled to vector sizes. This allows fairly complicated coalesce strategies (such as take from first two vectors if possible, else write in zero) to be expressed very succinctly:

vec1 <- c(1, 2, NA, NA)
vec2 <- c(10, NA, 20, NA) 
vec1 %?% vec2 %?% 0
# [1]  1  2 20  0

Categories: Administrativia Coding

Tagged as: Programming R wrapr

jmount

Data Scientist and trainer at Win Vector LLC. One of the authors of Practical Data Science with R.