listless

A lightweight R package for converting lists to tidy data frames.

Installation

To install the stable version, type:

install.packages("listless")

To install the development version, you first need the devtools package.

install.packages("devtools")

Then you can install the listless package using

devtools::install_bitbucket("graumannlabtools/listless")

Functions

list_to_data.frame

Converts a list to a tidy data.frame.

For example:

library(listless)
library(magrittr)
l <- list(
  a = 1,
  2:3,                             # missing names are blank
  c = list(ca = 4:6, 7:10, list(cca = 11:15)),
  d = list()                       # empty elt's silently ignored
)
list_to_data.frame(l)

##    names names.1 names.2 values
## 1      a    <NA>    <NA>      1
## 2           <NA>    <NA>      2
## 3           <NA>    <NA>      3
## 4      c      ca    <NA>      4
## 5      c      ca    <NA>      5
## 6      c      ca    <NA>      6
## 7      c            <NA>      7
## 8      c            <NA>      8
## 9      c            <NA>      9
## 10     c            <NA>     10
## 11     c             cca     11
## 12     c             cca     12
## 13     c             cca     13
## 14     c             cca     14
## 15     c             cca     15

# You can set custom column names
list_to_data.frame(l, c("group", "subgroup", "element"), "amount") %>% 
  head(3)

##   group subgroup element amount
## 1     a     <NA>    <NA>      1
## 2           <NA>    <NA>      2
## 3           <NA>    <NA>      3

list_str

Summarises the contents of a list, in a tidy data.frame.

For example:

l2 <- list(
  a = 1,
  b = matrix(1:6, 2),
  c = list(
    ca = y ~ x,
    list(cba = median, cbb = quote(1 + 1), cbc = expression(1 + 1)),
    cc = list(cca = as.name("xyz"))
  ),
  d = array(1:24, 2:4)
)
list_str(l2)

##   names names.1 names.2      class       mode length    dims
## 1     a    <NA>    <NA>    numeric    numeric      1        
## 2     b    <NA>    <NA>     matrix    numeric      6    2, 3
## 3     c      ca    <NA>    formula       call      3        
## 4     c     cba    <NA>   function   function      1        
## 5     c     cbb    <NA>       call       call      3        
## 6     c     cbc    <NA> expression expression      1        
## 7     c      cc     cca       name       name      1        
## 8     d    <NA>    <NA>      array    numeric     24 2, 3, 4

list_depth

Returns the depth (number of nested levels) of a list.

For example:

list_depth(l)

## [1] 3

# Atomic variables have depth 0
list_depth(1)

## [1] 0

# Empty elements can be pruned before counting
list_depth(list())

## [1] 1

list_depth(list(), prune_empty_elts = TRUE)

## [1] 0