This vignette describes the statistics collated by
pkgstats. The first section provides full descriptions of
all data returned by the
main pkgstats() function, and the second section
describes the output of the
pkgstats_summary() function which converts statistics
to a single-row summary. Single-row summaries from multiple packages can
be combined to represent the statistical properties of multiple packages
in a single data.frame object. The
pkgstats() function is applied to all CRAN packages on
a regular basis, with results accessible with the
dl_pkgstats_data() function.
Overview of Package Statistics
The main
pkgstats() function returns a list of
eight main components:
-
"loc"summarising “Lines of Code” in package sub-directories and languages; -
"vignettes"containing counts of numbers of vignettes and demos; -
"data_stats"summarising data files; -
"desc"summarising the contents of the package “DESCRIPTION” file; -
"translations"summarising translations into other (human) languages; -
"objects": a table of all “objects” in all languages; -
"network": a table of relationships between objects, such as function calls; and -
"external_calls": a detailed table of all calls made to all R functions.
The following sub-sections provide further detail on these components
(except the simpler components of "vignettes",
"data_stats", and "translations"). The results
use the output of applying the function to the source code of this
package:
s <- pkgstats () # run in root directory of `pkgstats` sourceThe result is a list of various data extracted from the code. All
except for objects and network represent
summary data:
s [!names (s) %in% c ("objects", "network", "external_calls")]
#> $loc
#> # A tibble: 4 × 11
#> language dir nfiles nlines ncode nempty nspaces nchars nexpr ntabs
#> <chr> <chr> <int> <int> <int> <int> <int> <int> <int> <int>
#> 1 C++ src 3 364 276 67 932 6983 1 0
#> 2 R R 24 4727 345 682 333 114334 1 0
#> 3 R tests 7 300 234 61 511 5543 1 0
#> 4 Rmd vignettes 2 347 278 61 1483 11290 1 0
#> # ℹ 1 more variable: indentation <int>
#>
#> $vignettes
#> vignettes demos
#> 2 0
#>
#> $data_stats
#> n total_size median_size
#> 0 0 0
#>
#> $desc
#> package verion date license
#> 1 pkgstats 0.1.1 Tue Nov 5 18:18:07 2024 GPL-3
#> urls
#> 1 https://docs.ropensci.org/pkgstats/,\nnhttps://github.com/ropensci-review-tools/pkgstats
#> bugs aut ctb fnd rev ths
#> 1 https://github.com/ropensci-review-tools/pkgstats/issues 1 0 0 0 0
#> trl depends imports
#> 1 0 NA brio, checkmate, dplyr, fs, igraph, methods, readr, sys, withr
#> suggests
#> 1 curl, hms, jsonlite, knitr, parallel, pkgbuild, Rcpp, rmarkdown, roxygen2, testthat, visNetwork
#> enchances linking_to
#> 1 <NA> cpp11
#>
#> $translations
#> [1] NAThese results demonstrate that many fields use NA to
denote values of zero. The following sub-sections explore these various
components generated by the pkgstats() function in more
detail.
Lines of Code
The first item in the above list is “loc” for Lines-of-Code, which
are counted using an internal routine specifically developed for R
packages, and which provides more accurate and R-specific information
than most open source code counting libraries. For example, the counts
in pkgstats are able to distinguish and separately count
code chunks and text lines in .Rmd files.
s$loc
#> # A tibble: 4 × 11
#> language dir nfiles nlines ncode nempty nspaces nchars nexpr ntabs
#> <chr> <chr> <int> <int> <int> <int> <int> <int> <int> <int>
#> 1 C++ src 3 364 276 67 932 6983 1 0
#> 2 R R 24 4727 345 682 333 114334 1 0
#> 3 R tests 7 300 234 61 511 5543 1 0
#> 4 Rmd vignettes 2 347 278 61 1483 11290 1 0
#> # ℹ 1 more variable: indentation <int>That output includes the following components, grouped by both computer language and package directory:
-
nfiles= Numbers of files in each directory and language. -
nlines= Total numbers of lines in all files. -
ncode= Total numbers of lines of code. -
ndoc= Total numbers of documentation or comment lines. -
nempty= Total numbers of empty of blank lines. -
nspaces= Total numbers of white spaces in all code lines, excluding leading indentation spaces. -
nchars= Total numbers of non-white-space characters in all code lines. -
nexpr= Median numbers of nested expressions in all lines which have any expressions (see below). -
ntabs= Number of lines of code with initial tab indentation. -
indentation= Number of spaces by which code is indented (with-1denoting tab-indentation).
Numbers of nested expressions are counted as numbers of brackets or braces of any type nested on a single line. The following line has one nested bracket:
x <- myfn ()while the following has four:
x <- function () { return (myfn ()) }Code with fewer nested expressions per line is generally easier to
read, and this metric is provided as one indication of the general
readability of code. A second relative indication may be extracted by
converting numbers of spaces and characters to a measure of relative
numbers of white spaces, noting that the nchars value
quantifies total characters including white spaces.
index <- which (s$loc$dir %in% c ("R", "src")) # consider source code only
sum (s$loc$nspaces [index]) / sum (s$loc$nchars [index])
#> [1] 0.01042723Finally, the ntabs statistic can be used to identify
whether code uses tab characters as indentation, otherwise the
indentation statistics indicate median numbers of white
spaces by which code is indented. The objects,
network, and external_calls items returned by
the pkgstats()
function are described further below.
"desc": The package “DESCRIPTION” file
The desc item looks like this:
s$desc
#> package verion date license
#> 1 pkgstats 0.1.1 Tue Nov 5 18:18:07 2024 GPL-3
#> urls
#> 1 https://docs.ropensci.org/pkgstats/,\nnhttps://github.com/ropensci-review-tools/pkgstats
#> bugs aut ctb fnd rev ths
#> 1 https://github.com/ropensci-review-tools/pkgstats/issues 1 0 0 0 0
#> trl depends imports
#> 1 0 NA brio, checkmate, dplyr, fs, igraph, methods, readr, sys, withr
#> suggests
#> 1 curl, hms, jsonlite, knitr, parallel, pkgbuild, Rcpp, rmarkdown, roxygen2, testthat, visNetwork
#> enchances linking_to
#> 1 <NA> cpp11This item includes the following components:
- Package name, version, date, and license
- Package URL(s) (
urls) - URL for BugReports (
bugs) - Number of contributors with role of author
(
desc_n_aut), contributor (desc_n_ctb), funder (desc_n_fnd), reviewer (desc_n_rev), thesis advisor (ths), and translator (trl, relating to translation between computer and not spoken languages). - Comma-separated character entries for all
depends,imports,suggests, andlinking_topackages.
The “Date” field is taken from the “Date/Publication” field
automatically inserted by CRAN on package publication, or for non-CRAN
packages to the “mtime” value (modification time) value of the
DESCRIPTION file. Note that “date” values extracted by
pkgstats do not use “Date” values from DESCRIPTION files
(as these are manually-entered, and potentially unreliable).
1.3 "objects": Objects in all languages
The objects item contains all code objects identified by
the code-tagging library ctags. For R, those are
primarily functions, but for other languages may be a variety of
entities such as class or structure definitions, or sub-members thereof.
Object tables look like this:
head (s$objects)
#> file_name fn_name kind language loc npars
#> 1 R/archive-trawl.R pkgstats_from_archive function R 89 9
#> 2 R/archive-trawl.R list_archive_files function R 17 2
#> 3 R/archive-trawl.R rm_prev_files function R 24 2
#> 4 R/archive-trawl.R pkgstats_fns_from_archive function R 82 7
#> 5 R/cpp11.R cpp_loc function R 3 4
#> 6 R/ctags-install.R clone_ctag function R 17 1
#> has_dots exported param_nchards_md param_nchards_mn num_doclines
#> 1 FALSE TRUE 133 159.7778 77
#> 2 FALSE FALSE NA NA NA
#> 3 FALSE FALSE NA NA NA
#> 4 FALSE TRUE 163 174.5714 50
#> 5 FALSE FALSE NA NA NA
#> 6 FALSE FALSE NA NA NAObjects are primarily sorted by language, with R-language objects given first. These are mostly functions, and include statistics on:
- lines of code used to define each function (
loc); - numbers of parameters (
npars); - whether or not the function includes a “three dots” parameter (that
is,
...; identified byhas_dots); - whether or not a function is exported (
exported); - Mean and median numbers of character used to document each parameter
(
param_nchards_mnandparam_nchards_md, respectively); and - Total number of lines of documentation for that object / function.
"network": Relationships between objects
The network item details all relationships between
objects, which generally reflects one object calling or otherwise
depending on another object. Each row thus represents one edge of a
“function call” network, with each entry in the from and
to columns representing the network vertices or nodes.
head (s$network)
#> file line1 from to
#> 1 R/external_calls.R 11 external_call_network extract_call_content
#> 2 R/external_calls.R 26 external_call_network add_base_recommended_pkgs
#> 3 R/external_calls.R 38 external_call_network add_other_pkgs_to_calls
#> 4 R/external_calls.R 326 add_other_pkgs_to_calls control_parse
#> 5 R/pkgstats-summary.R 39 pkgstats_summary null_stats
#> 6 R/pkgstats-summary.R 50 pkgstats_summary loc_summary
#> language cluster_dir centrality_dir cluster_undir centrality_undir
#> 1 R 1 9 1 230.8333
#> 2 R 1 9 1 230.8333
#> 3 R 1 9 1 230.8333
#> 4 R 1 1 1 6.0000
#> 5 R 1 11 1 874.0000
#> 6 R 1 11 1 874.0000
nrow (s$network)
#> [1] 142The network table includes additional statistics on the centrality of
each edge, measured as betweenness centrality assuming edges to be both
directed (centrality_dir) and undirected
(centrality_undir). More central edges reflect connections
between objects that are more central to package functionality, and vice
versa. The distinct components of the network are also represented by
discrete cluster numbers, calculated both for directed and undirected
versions of the network. Each distinct cluster number represents a
distinct group of objects, internally related to other members of the
same cluster, yet independent of all objects with different cluster
numbers.
The network can be viewed as an interactive vis.js network through
passing the result of pkgstats – the variable
p in the code above – to the plot_network()
function.
"external_calls": All calls made to all R
functions
The external_calls item is structured similar to the
network object, but identifies all calls to functions from
external packages. However, unlike the network and
object data, which provide information on objects and
relationships in all computer languages used within a package, the
external_calls object maps calls within R code only, in
order to provide insight into the use within a package of of functions
from other packages, including R’s base and recommended packages. The
object looks like this:
head (s$external_calls)
#> tags_line call tag file kind start end package
#> 1 1 c GTAGSLABEL R/ctags-test.R nameattr 109 109 base
#> 2 2 character file_name R/pkgstats.R nameattr 185 185 base
#> 3 3 character fn_name R/pkgstats.R nameattr 186 186 base
#> 4 4 logical has_dots R/pkgstats.R nameattr 189 189 base
#> 5 5 integer loc R/pkgstats.R nameattr 187 187 base
#> 6 6 left_join name R/plot.R nameattr 89 89 dplyrThese data are converted to a summary form by the pkgstats_summary()
function, which tabulates numbers of external calls and unique
functions from each package. These data are presented as a single
character string which looks like this:
s_summ <- pkgstats_summary (s)
print (s_summ$external_calls)These data can be easily converted to the corresponding numeric values using code like the following:
x <- strsplit (s_summ$external_calls, ",") [[1]]
x <- do.call (rbind, strsplit (x, ":"))
x <- data.frame (
pkg = x [, 1],
n_total = as.integer (x [, 2]),
n_unique = as.integer (x [, 3])
)
x$n_total_rel <- round (x$n_total / sum (x$n_total), 3)
x$n_unique_rel <- round (x$n_unique / sum (x$n_unique), 3)
print (x)
#> pkg n_total n_unique n_total_rel n_unique_rel
#> 1 base 581 84 0.704 0.426
#> 2 brio 11 2 0.013 0.010
#> 3 curl 4 3 0.005 0.015
#> 4 dplyr 7 4 0.008 0.020
#> 5 fs 4 2 0.005 0.010
#> 6 graphics 10 2 0.012 0.010
#> 7 hms 2 1 0.002 0.005
#> 8 igraph 3 3 0.004 0.015
#> 9 parallel 2 1 0.002 0.005
#> 10 pkgstats 126 73 0.153 0.371
#> 11 readr 8 5 0.010 0.025
#> 12 stats 19 3 0.023 0.015
#> 13 sys 14 1 0.017 0.005
#> 14 tools 3 2 0.004 0.010
#> 15 utils 22 7 0.027 0.036
#> 16 visNetwork 3 2 0.004 0.010
#> 17 withr 6 2 0.007 0.010Those data reveal, for example, that this package makes 581 individual calls to 84 unique functions from the “base” package.