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Intro to csutil

Splitting

csutil::easy_split(letters[1:20], size_of_each_group = 3)
#> $`1`
#> [1] "a" "b" "c"
#> 
#> $`2`
#> [1] "d" "e" "f"
#> 
#> $`3`
#> [1] "g" "h" "i"
#> 
#> $`4`
#> [1] "j" "k" "l"
#> 
#> $`5`
#> [1] "m" "n" "o"
#> 
#> $`6`
#> [1] "p" "q" "r"
#> 
#> $`7`
#> [1] "s" "t"
csutil::easy_split(letters[1:20], number_of_groups = 3)
#> $`1`
#> [1] "a" "b" "c" "d" "e" "f" "g"
#> 
#> $`2`
#> [1] "h" "i" "j" "k" "l" "m" "n"
#> 
#> $`3`
#> [1] "o" "p" "q" "r" "s" "t"

Unnesting data.frames

x <- list(
  list(
    "a" = data.frame("v1"=1),
    "b" = data.frame("v2"=3)
  ),
  list(
    "a" = data.frame("v1"=10),
    "b" = data.frame("v2"=30),
    "d" = data.frame("v3"=50)
  )
)
print(x)
#> [[1]]
#> [[1]]$a
#>   v1
#> 1  1
#> 
#> [[1]]$b
#>   v2
#> 1  3
#> 
#> 
#> [[2]]
#> [[2]]$a
#>   v1
#> 1 10
#> 
#> [[2]]$b
#>   v2
#> 1 30
#> 
#> [[2]]$d
#>   v3
#> 1 50
csutil::unnest_dfs_within_list_of_fully_named_lists(x)
#> $a
#>    v1
#> 1:  1
#> 2: 10
#> 
#> $b
#>    v2
#> 1:  3
#> 2: 30
#> 
#> $d
#>    v3
#> 1: 50

Describing lists

csutil::is_fully_named_list(list(1))
#> [1] FALSE
csutil::is_fully_named_list(list("a"=1))
#> [1] TRUE

csutil::is_all_list_elements_null_or_df(list(data.frame()))
#> [1] TRUE
csutil::is_all_list_elements_null_or_df(list(1, NULL))
#> [1] FALSE

csutil::is_all_list_elements_null_or_list(list(1, NULL))
#> [1] FALSE
csutil::is_all_list_elements_null_or_list(list(list(), NULL))
#> [1] TRUE

csutil::is_all_list_elements_null_or_fully_named_list(list(list(), NULL))
#> [1] FALSE
csutil::is_all_list_elements_null_or_fully_named_list(list(list("a" = 1), NULL))
#> [1] TRUE

Apply a function via hash table

This function extracts the unique input values, applies the given function to it to create a hash table (containing unique input/output combinations), and then matches the original input to the hash table to obtain the desired output.

This can dramatically speed up computation if there is a lot of data and a limited amount of unique values.

input <- rep(seq(as.Date("2000-01-01"), as.Date("2020-01-01"), 1), 1000)
a1 <- Sys.time()
z <- format(input, "%Y")
a2 <- Sys.time()
a2 - a1
#> Time difference of 2.071753 secs

b1 <- Sys.time()
z <- csutil::apply_fn_via_hash_table(
  input,
  format,
  "%Y"
)
b2 <- Sys.time()
b2 - b1
#> Time difference of 0.6172273 secs

These binaries (installable software) and packages are in development.
They may not be fully stable and should be used with caution. We make no claims about them.