| Title: | Common Base-R Problems Relating to Lists |
|---|---|
| Description: | Utility functions that help with common base-R problems relating to lists. Lists in base-R are very flexible. This package provides functions to quickly and easily characterize types of lists. That is, to identify if all elements in a list are null, data.frames, lists, or fully named lists. Other functionality is provided for the handling of lists, such as the easy splitting of lists into equally sized groups, and the unnesting of data.frames within fully named lists. |
| Authors: | Richard Aubrey White [aut, cre] (ORCID: <https://orcid.org/0000-0002-6747-1726>) |
| Maintainer: | Richard Aubrey White <[email protected]> |
| License: | MIT + file LICENSE |
| Version: | 2023.4.25 |
| Built: | 2026-07-01 09:39:13 UTC |
| Source: | https://github.com/niphr/csutil |
Extracts the unique values of x, applies fn to those unique
values, and maps the results back to the original vector. This avoids
redundant computation when x contains many repeated values.
apply_fn_via_hash_table(x, fn, ...)apply_fn_via_hash_table(x, fn, ...)
x |
A vector whose values need a function applied. |
fn |
A function to apply to the unique values of |
... |
Additional arguments passed to |
This can dramatically speed up computation if there is a lot of data and
a limited number of unique values: fn is called once per unique value
rather than once per element.
A vector of the same length as x, containing the result of
applying fn to each element (computed via unique-value lookup).
x <- c("a", "b", "a", "c", "b", "a") apply_fn_via_hash_table(x, toupper) # passing extra arguments to fn nums <- c(1.1, 2.2, 1.1, 3.3) apply_fn_via_hash_table(nums, round, digits = 0)x <- c("a", "b", "a", "c", "b", "a") apply_fn_via_hash_table(x, toupper) # passing extra arguments to fn nums <- c(1.1, 2.2, 1.1, 3.3) apply_fn_via_hash_table(nums, round, digits = 0)
Easily split a list into a list of equally sized vectors.
easy_split(x, size_of_each_group = NULL, number_of_groups = NULL)easy_split(x, size_of_each_group = NULL, number_of_groups = NULL)
x |
The vector to be split |
size_of_each_group |
If you want to split 'x' into a number of groups, each of 'size_of_each_group' size |
number_of_groups |
How many equally sized groups do you want? |
You can either specify the length of the list (via 'number_of_groups') or the length of the equally sized vectors within each list element (via 'size_of_each_group'). The last element of the list can be shorter than the other elements.
A list containing equally sized vectors.
easy_split(letters[1:20], size_of_each_group = 3) easy_split(letters[1:20], number_of_groups = 3)easy_split(letters[1:20], size_of_each_group = 3) easy_split(letters[1:20], number_of_groups = 3)
Checks if A) 'x' is a list, B) All elements in 'x' are either null or data.frame.
is_all_list_elements_null_or_df(x)is_all_list_elements_null_or_df(x)
x |
An object |
Boolean.
is_all_list_elements_null_or_df(data.frame()) is_all_list_elements_null_or_df(list(data.frame())) is_all_list_elements_null_or_df(list(1, NULL)) is_all_list_elements_null_or_df(list(data.frame(), NULL)) is_all_list_elements_null_or_df(list("a"=1, 2))is_all_list_elements_null_or_df(data.frame()) is_all_list_elements_null_or_df(list(data.frame())) is_all_list_elements_null_or_df(list(1, NULL)) is_all_list_elements_null_or_df(list(data.frame(), NULL)) is_all_list_elements_null_or_df(list("a"=1, 2))
Checks if A) 'x' is a list, B) All elements in 'x' are either null or fully named lists.
is_all_list_elements_null_or_fully_named_list(x)is_all_list_elements_null_or_fully_named_list(x)
x |
An object |
Fully named lists are lists with each element having a name.
Boolean.
is_all_list_elements_null_or_fully_named_list(data.frame()) is_all_list_elements_null_or_fully_named_list(list(data.frame())) is_all_list_elements_null_or_fully_named_list(list(1, NULL)) is_all_list_elements_null_or_fully_named_list(list(list(), NULL)) is_all_list_elements_null_or_fully_named_list(list(list("a" = 1), NULL)) is_all_list_elements_null_or_fully_named_list(list("a"=1, 2))is_all_list_elements_null_or_fully_named_list(data.frame()) is_all_list_elements_null_or_fully_named_list(list(data.frame())) is_all_list_elements_null_or_fully_named_list(list(1, NULL)) is_all_list_elements_null_or_fully_named_list(list(list(), NULL)) is_all_list_elements_null_or_fully_named_list(list(list("a" = 1), NULL)) is_all_list_elements_null_or_fully_named_list(list("a"=1, 2))
Checks if A) 'x' is a list, B) All elements in 'x' are either null or list.
is_all_list_elements_null_or_list(x)is_all_list_elements_null_or_list(x)
x |
An object |
Boolean.
is_all_list_elements_null_or_list(data.frame()) is_all_list_elements_null_or_list(list(data.frame())) is_all_list_elements_null_or_list(list(1, NULL)) is_all_list_elements_null_or_list(list(list(), NULL)) is_all_list_elements_null_or_list(list("a"=1, 2))is_all_list_elements_null_or_list(data.frame()) is_all_list_elements_null_or_list(list(data.frame())) is_all_list_elements_null_or_list(list(1, NULL)) is_all_list_elements_null_or_list(list(list(), NULL)) is_all_list_elements_null_or_list(list("a"=1, 2))
Checks if 'x' is a list with each element named.
is_fully_named_list(x)is_fully_named_list(x)
x |
An object |
Boolean.
is_fully_named_list(list()) is_fully_named_list(list(1)) is_fully_named_list(list("a"=1)) is_fully_named_list(list("a"=1, 2))is_fully_named_list(list()) is_fully_named_list(list(1)) is_fully_named_list(list("a"=1)) is_fully_named_list(list("a"=1, 2))
Consider the situation where a function returns a list containing two data.frames. If this function is called repeatedly and the return values are stored in a list, we will have a list of fully named lists (each of which contains a data.frame). Typically, we want to extract the two data.frames from this nested list structure (and rbindlist them).
unnest_dfs_within_list_of_fully_named_lists( x, returned_name_when_dfs_are_not_nested = "data", ... )unnest_dfs_within_list_of_fully_named_lists( x, returned_name_when_dfs_are_not_nested = "data", ... )
x |
A list of fully named lists (which then contain data.frames) |
returned_name_when_dfs_are_not_nested |
When x is a single list of data.frames, what name should be returned? |
... |
parameters passed to data.table::rbindlist |
Fully named list, each element containing a data.table.
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) ), list( "a" = NULL ), NULL ) print(x) csutil::unnest_dfs_within_list_of_fully_named_lists(x) x <- list( data.frame("v1"=1), data.frame("v3"=50) ) print(x) csutil::unnest_dfs_within_list_of_fully_named_lists( x, returned_name_when_dfs_are_not_nested = "NAME", fill = TRUE )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) ), list( "a" = NULL ), NULL ) print(x) csutil::unnest_dfs_within_list_of_fully_named_lists(x) x <- list( data.frame("v1"=1), data.frame("v3"=50) ) print(x) csutil::unnest_dfs_within_list_of_fully_named_lists( x, returned_name_when_dfs_are_not_nested = "NAME", fill = TRUE )