When teaching students how to clean data, it helps to have data that isn’t too clean already. salty offers functions for “salting” clean data with problems often found in datasets in the wild, such as:
Install salty from CRAN with:
install.packages("salty")
You may install the development version of salty from github with:
# install.packages("devtools")
::install_github("mdlincoln/salty") devtools
library(salty)
set.seed(10)
# We'll use charlatan to create some sample data
<- charlatan::ch_name(10)
sample_names
sample_names#> [1] "Bradyn Witting" "Glenn Trantow PhD"
#> [3] "Mariano Tromp-Willms" "Donte Beatty"
#> [5] "Jax Lueilwitz" "Esperanza Hane-Reichert"
#> [7] "Mr. Muhammad Zboncak DDS" "Mr. Cordero Effertz PhD"
#> [9] "Jacquline Hand" "Dr. Newman Dietrich Sr."
<- charlatan::ch_double(10)
sample_numbers
sample_numbers#> [1] -1.26519802 -0.37366156 -0.68755543 -0.87215883 -0.10176101 -0.25378053
#> [7] -1.85374045 -0.07794607 0.96856634 0.18492596
salty offers several easy-to-use functions for adding common problems to your data.
# Add in erroneous letters or punctuation
salt_letters(sample_names)
#> [1] "Bradyn Witting" "Glenn Trantow PhD"
#> [3] "Mariano Tromp-Willms" "Donte Beatty"
#> [5] "oJax Lueilwitz" "Esperanza Hane-Reichert"
#> [7] "Mr. Muhammad Zboncak DDS" "Mr. Cordero Effertz PhD"
#> [9] "JacqulTine Hand" "Dr. Newman Dietrich Sr."
salt_punctuation(sample_names)
#> [1] "Bradyn Witting" "Gl,enn Trantow PhD"
#> [3] "Mariano Tromp-Willms" "Donte Beatty"
#> [5] "Jax Lueilwitz" "Esperanza Hane-Reichert"
#> [7] "Mr. Muhammad Zboncak DDS" "Mr.' Cordero Effertz PhD"
#> [9] "Jacquline Hand" "Dr. Newman Dietrich Sr."
# Flip capitals
salt_capitalization(sample_names)
#> [1] "Bradyn Witting" "Glenn Trantow PhD"
#> [3] "MArIano Tromp-WillmS" "Donte Beatty"
#> [5] "Jax Lueilwitz" "Esperanza Hane-Reichert"
#> [7] "Mr. Muhammad Zboncak DDS" "Mr. Cordero Effertz PhD"
#> [9] "Jacquline Hand" "Dr. Newman Dietrich Sr."
# Introduce OCR errors. You can specify the proportion of values in the vector
# that should be salted, and the proportion of possible matches within a single
# value that should be changed.
salt_ocr(sample_names, p = 1, rep_p = 1)
#> [1] "Bradyn Witti'ng" "Glenn Tratltovvv PhD"
#> [3] "Mariallo Tromp-Willms" "DoInte Beatty"
#> [5] "Jax Lueilwvitz" "Esperanza Hane-Reiclhert"
#> [7] "MIr. Muhammad ZboIncak DDS" "MIr. Cordero Effertz PhD"
#> [9] "Jacqll1i'ne Ha nd" "Dr. Newvman Dietriclh Sr."
salt_delete
will simply drop characters from randomly
selected values in a vector, while salt_empty
and
salt_na
will replace entire values.
salt_delete(sample_names, p = 0.5, n = 6)
#> [1] "rdy Witg" "Glenn Trantow PhD"
#> [3] "Maiano romp-Wl" "Donte Beatty"
#> [5] "Jax Lueilwitz" "Esprna Hne-Rechrt"
#> [7] "Mr. Muhad Zocak DS" "Mr. Cordero Effertz PhD"
#> [9] "Jaulin n" "Dr. Newman Dietrich Sr."
salt_empty(sample_names, p = 0.5)
#> [1] "" "Glenn Trantow PhD"
#> [3] "" "Donte Beatty"
#> [5] "Jax Lueilwitz" "Esperanza Hane-Reichert"
#> [7] "" "Mr. Cordero Effertz PhD"
#> [9] "" ""
salt_na(sample_names, p = 0.5)
#> [1] "Bradyn Witting" "Glenn Trantow PhD"
#> [3] "Mariano Tromp-Willms" NA
#> [5] NA NA
#> [7] "Mr. Muhammad Zboncak DDS" NA
#> [9] NA "Dr. Newman Dietrich Sr."
For more fine-grained control over the salting process, and for access to a wider range of salting types, you can use the underlying functions provided for: inserting, substituting, replacing.
The set of insertions and replacements are specified via
shakers
, pre-filled character sets and pattern/replacement
pairs that the salt
verbs then call.
available_shakers()
#> $shaker
#> [1] "punctuation" "lowercase_letters" "uppercase_letters"
#> [4] "mixed_letters" "whitespace" "digits"
#>
#> $replacement_shaker
#> [1] "ocr_errors" "capitalization" "decimal_commas"
salt_insert
keeps all the characters in the original
while adding new ones, while salt_substitute
overwrites
those characters.
# Use p to specify the percent of values that you would like to salt
salt_insert(sample_names, shaker$punctuation, p = 0.5)
#> [1] "Bradyn Witting" "Glenn #Trantow PhD"
#> [3] "Mariano Tromp-Willms" "(Donte Beatty"
#> [5] "Jax Lue*ilwitz" "Esperanza H'ane-Reichert"
#> [7] "Mr. Muhammad Zbo'ncak DDS" "Mr. Cordero Effertz PhD"
#> [9] "Jacquline Hand" "Dr. Newman Dietrich Sr."
# Use n to specify how many new insertions/substitutions you want to make to selected values
salt_substitute(sample_names, shaker$punctuation, p = 0.5, n = 3)
#> [1] "Bradyn Witting" "Glenn Trantow PhD"
#> [3] "Maria#o /r(mp-Willms" "%onte B\"atty%"
#> [5] "Jax Lueil)i\"@" "Espe#a)za Hane(Reichert"
#> [7] "Mr. Muhammad Zboncak DDS" "Mr. Cordero Effertz PhD"
#> [9] "J'cqu/ine(Hand" "Dr. Newman Dietrich Sr."
Different flavors of salt are available using shaker
,
however you can also supply your own character vector of possible
replacements if you like.
salt_insert(sample_names, shaker$mixed_letters, p = 0.5)
#> [1] "ABradyn Witting" "Glenn Tqrantow PhD"
#> [3] "Mariano Tromp-Willms" "Donte Beatty"
#> [5] "Jaxx Lueilwitz" "Esperanza Hane-Reichert"
#> [7] "Mr. Muhammad Zboncak DDS" "Mr. Cordero TEffertz PhD"
#> [9] "Jacquline Handg" "Dr. Newman Dietrich Sr."
salt_insert(sample_numbers, shaker$digits, p = 0.5)
#> [1] "-1.26519850215309" "-0.373661555154702" "-0.687555430387918"
#> [4] "-30.87215882671769" "-0.101761006224816" "-0.2537680530102462"
#> [7] "-1.853740454457914" "-0.0779460660753655" "0.96856634052454"
#> [10] "0.1849259599590315"
salt_insert(sample_names, c("foo", "bar", "baz"), p = 0.5)
#> [1] "Bradyn Witting" "Glenn Trantow PhD"
#> [3] "barMariano Tromp-Willms" "Donte bazBeatty"
#> [5] "Jax Lueilwitz" "Efoosperanza Hane-Reichert"
#> [7] "Mr. Muhammad Zboncak DDS" "Mr. Corfoodero Effertz PhD"
#> [9] "Jacquline Handbaz" "Dr. Newman Dietrich Sr."
salt_replace
is a bit more targeted: it works with pairs
of patterns and replacements, either contained in
replacement_shaker
or user-specified. Use
rep_p
to set a probability of how many possible
replacements should actually get swapped out for any given value.
salt_replace(sample_names, replacement_shaker$ocr_errors, p = 1, rep_p = 1)
#> [1] "Bradyn Witti'ng" "Glenn Tratltovvv PhD"
#> [3] "Mariallo Tromp-Willms" "DoInte Beatty"
#> [5] "Jax Lueilwvitz" "Esperanza Hane-Reiclhert"
#> [7] "MIr. Muhammad ZboIncak DDS" "MIr. Cordero Effertz PhD"
#> [9] "Jacqll1i'ne Ha nd" "Dr. Newvman Dietriclh Sr."
salt_replace(sample_names, replacement_shaker$capitalization, p = 0.5, rep_p = 0.2)
#> [1] "BRadyn WiTting" "Glenn Trantow PhD"
#> [3] "Mariano Tromp-Willms" "DoNte Beatty"
#> [5] "JAx LuEiLwitZ" "Esperanza Hane-Reichert"
#> [7] "Mr. Muhammad Zboncak DDS" "Mr. Cordero Effertz PhD"
#> [9] "JAcquline HAnd" "Dr. Newman DiETrICh Sr."
salt_replace(sample_numbers, replacement_shaker$decimal_commas, p = 0.5, rep_p = 1)
#> [1] "-1.2651980215309" "-0.373661555154702" "-0.687555430387918"
#> [4] "-0,87215882671769" "-0.101761006224816" "-0,253780530102462"
#> [7] "-1,85374045447914" "-0.0779460660753655" "0,96856634052454"
#> [10] "0,184925959990315"
You may also specify your own arbitrary character vector of possible insertions.
salt_insert(sample_names, insertions = c("X", "Z"))
#> [1] "XBradyn Witting" "Glenn Trantow PhD"
#> [3] "Mariano Tromp-Willms" "DoXnte Beatty"
#> [5] "Jax Lueilwitz" "Esperanza Hane-Reichert"
#> [7] "Mr. Muhammad Zboncak DDS" "Mr. Cordero Effertz PhD"
#> [9] "Jacquline Hand" "Dr. Newman Dietrich Sr."
salty should not be used for anonymizing data; that’s not its purpose. However, it does draw some inspiration from anonymizer.
To create sample data for salting, take a look at charlatan.
The common OCR replacement errors are partially derived from the
sed
replacements specified in the Royal
Society Corpus project: Knappen, Jörg, Fischer, Stefan, Kermes,
Hannah, Teich, Elke, and Fankhauser, Peter. 2017. “The Making of the
Royal Society Corpus.” In Proceedings of the NoDaLiDa 2017 Workshop
on Processing Historical Language. Göteborg, Sweden. Linköping
University Electronic Press. https://aclanthology.org/W17-0503.pdf.