Re-encoding people in the EDH dataset

Preliminaries

Install and load a version of "sdam" package.

install.packages("sdam") # from CRAN
devtools::install_github("sdam-au/sdam") # development version
devtools::install_github("mplex/cedhar", subdir="pkg/sdam") # legacy version R 3.6.x
# load and check versions
library(sdam)
packageVersion("sdam")
[1] '1.1.4'

EDH people

  • EDH is a dataset in "sdam" that contains the texts of Latin and Latin-Greek inscriptions of the Roman Empire, which have been retrieved from the Epigraphic Database Heidelberg API repository through routines get.edh() and get.edhw().

Since the year 2022 and still today, the API repository does not support people variables, and the EDH dataset serves as an alternative for the analysis of people-related inscriptions.

One challenge with people variables in EDH is that some records contain characters in Greek and Latin extended that need re-encoding for a proper rendering and display.

Re-encoding people in EDH

Ancient inscriptions in some Roman provinces have Greek characters written and, due to encoding and decoding steps in the process of extraction, loading, and transformation of the data (perhaps Treating UTF-8 Bytes as Windows-1252?), Greek and other Latin characters are not displayed properly with the actual version of the EDH dataset. Most of the encoding issues are in variables related to people, and some examples with inscriptions in Roman provinces are next.

Achaia

The Roman province of Achaia in the EDH dataset has inscriptions related to people.

Roman province of Achaia (ca 117 AD).

Roman province of Achaia (ca 117 AD).

Function edhw() is to obtain the available inscriptions per province in the EDH dataset, which is a list that is the input for the same function to extract people variables cognomen and nomen. In this case, the 'province' argument is Ach that stands for Achaia.

# select two people variables from Achaia
Ach <- edhw(province="Ach") |> 
  edhw(vars="people", select=c("cognomen","nomen"))
Error in `is.null(unlist(w)) == FALSE && is.na(unlist(w)) == FALSE`:
! 'length = 17' in coercion to 'logical(1)'

There are 1539 records with people in Ach that corresponds to the number of rows in this data frame.

# number of people entries in Achaia
nrow(Ach)
Error:
! object 'Ach' not found

However, some records have either missing data or are inscriptions where cognomen and nomen are not available.

# also remove NAs
Ach <- edhw(province="Ach") |> 
  edhw(vars="people", select=c("cognomen","nomen"), na.rm=TRUE)

nrow(Ach)
Error in `is.null(unlist(w)) == FALSE && is.na(unlist(w)) == FALSE`:
! 'length = 17' in coercion to 'logical(1)'
Error:
! object 'Ach' not found

Clean function for re-encoding

Treating with people attribute variables requires many times re-encoding that is one option in function cln(). For instance, values in cognomen in the first entries of Ach are likely in Greek.

# some people entries in Achaia
head(Ach)
Error:
! object 'Ach' not found

Function cln() serves to re-encode Greek and Latin characters to render Greek, Greek extended, and Latin extended glyphs.

# re-encode in Ach cognomen
Ach$cognomen |> 
  head() |> 
  cln()
cognomen
Error:
! object 'Ach' not found


Error:
! object 'Ach' not found


Error:
! object 'Ach' not found


Error:
! object 'Ach' not found


Error:
! object 'Ach' not found


Error:
! object 'Ach' not found

For cognomen in the last people entries in Achaia.

# last entries
tail(Ach)
Error:
! object 'Ach' not found

After re-encoding the last records in Ach with cln(), it is easier to see, for example, that some have identical cognomen where entries having <NA> in the input become NA.

# clean last entries of cognomen
Ach$cognomen |> 
  tail() |> 
  cln()
cognomen
Error:
! object 'Ach' not found


Error:
! object 'Ach' not found


Error:
! object 'Ach' not found


Error:
! object 'Ach' not found


Error:
! object 'Ach' not found


Error:
! object 'Ach' not found
# clean last entries of nomen
Ach$nomen |> 
  tail() |> 
  cln()
nomen
Error:
! object 'Ach' not found


Error:
! object 'Ach' not found


Error:
! object 'Ach' not found


Error:
! object 'Ach' not found


Error:
! object 'Ach' not found


Error:
! object 'Ach' not found

Re-encode Greek and Latin within data frames

Aegyptus

In the case of the province of Aegyptus, three people variables have a mixing og Greek and Latin characters scripted that need re-codification as well.

Roman province of Aegyptus (ca 117 AD).

Roman province of Aegyptus (ca 117 AD). 

# Aegyptus people
Aeg <- edhw(province="Aeg") |> 
  edhw(vars="people")
Error in `is.null(unlist(w)) == FALSE && is.na(unlist(w)) == FALSE`:
! 'length = 4' in coercion to 'logical(1)'
# three variables of the last eight records
Aeg[ , c(3,5:6)] |> 
  tail(8)
Error:
! object 'Aeg' not found

For people in Aegyptus, columns three, and five to six correspond to cognomen, name, and nomen, where the output from cln() in the console is a dataframe.

# re-encode three variables from last entries
Aeg[ ,c(3,5:6)] |> 
  tail() |> 
  cln()
cognomen
Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found


name
Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found


nomen
Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found


Some entries in Aeg have Greek extended characters, and one entry in Latin has a special character at the end (Sulpicius*), which can be omitted for further computations by raising the cleaning level to 2.

nomen in Aegyptus

Benefits from re-encoding and cleaning text from the EDH dataset are evident like when counting occurrences in the different attribute variables as with nomen in Aeg.

# default cleaning level 1
Aeg$nomen |> 
  cln() |> 
  table() |> 
  sort(decreasing=TRUE)
Error:
! object 'Aeg' not found
Error:
! object 'Aeg' not found
Error:
! object 'Aeg' not found
Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found
Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found
Error:
! object 'Aeg' not found


etc.

...

By raising the cleaning level to 2, all special characters are removed from the end, and it is possible to see that, in the Roman province of Aegyptus, Sempronius, Sentius, Valerius are the three most common nomen in inscriptions with four occurrences each.

# raise cleaning level and remove NAs
Aeg$nomen |> 
  cln(level=2, na.rm=TRUE) |> 
  table() |> 
  sort(decreasing=TRUE) 
Error:
! object 'Aeg' not found
Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found
Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found
Error:
! object 'Aeg' not found


Error:
! object 'Aeg' not found
Error:
! object 'Aeg' not found


etc.

...

Caveats

See Warnings section in manual.