The functionality of this package allows to extract the information from EXFOR entries given as character strings and put it into a nested list that can be easily handled in R. It is also possible to convert EXFOR entries to JSON objects that can be conveniently imported in other high-level languages such as Python.
Being an R package, it requires the R interpreter and depends on the Rcpp package.
The package can be installed from the command line via
git clone https://github.com/gschnabel/exforParser.git
R CMD INSTALL exforParser
The following code snippet shows how to load an entry from a file:
library(exforParser)
# read an EXFOR entry from a file into a character string
# exforFilePath can be replaced by a hard-coded string pointing to
# some other file containing an EXFOR entry
exforFilePath <- system.file("extdata", "entry_20917.txt", package="exforParser")
# An alternative EXFOR entry for exploration:
# exforFilePath <- system.file("extdata", "entry_22871.txt", package="exforParser")
exforEntry <- paste0(readLines(exforFilePath), collapse="\n")
# extract the information from the character string
# and convert it to a nested list
exforList <- parseEntry(exforEntry)
All EXFOR entries (the complete EXFOR database) can be downloaded from http://www.nucleardata.com.
The variable exforList is a nested list which gives convenient
access to the various fields of the EXFOR entry.
Here are some exemplary commands that show how information
of an EXFOR entry can be accessed:
# show names of the top-level elements
names(exforList)
# show number of subentries in the entry
length(exforList$SUBENT)
# show the first subentry
exforList$SUBENT[[1]]
# show the author information
exforList$SUBENT[[1]]$BIB$AUTHOR
# show the detector used
exforList$SUBENT[[1]]$BIB$DETECTOR
# show the column names of the DATA table
exforList$SUBENT[[2]]$DATA$DESCR
# show the units of the columns in the DATA table
exforList$SUBENT[[2]]$DATA$UNIT
# show the DATA table itself
exforList$SUBENT[[2]]$DATA$TABLE
If the data should be exported to another programming language, the JSON format can be used as intermediate format:
jsonString <- convToJSON(exforList)
cat(jsonString, file="testfile.json")
# file is created in the working directory
# check with the command 'getwd()' to figure out
# the current working directory
It is also possible to export only a few subentries of the EXFOR entry:
jsonString <- convToJSON(exforList$SUBENT[1:3])
cat(jsonString, file="testfile.json")
For working with the EXFOR data, it may be convenient to
add the general information in the first subentry
to another subentry of the same EXFOR entry.
Another simplification is the inclusion of the information
in the COMMON blocks to the DATA block, even if this
means duplication of information.
Finally, it facilitates processing if units are standardized,
i.e. all energies given as MeV and cross sections given as
millibarn.
The mentioned transformations can be performed using
function transformSubent:
transfSubent <- transformSubent(exforList$SUBENT[[1]], exforList$SUBENT[[2]])
The first argument has to be the first subentry and the second argument can be any of the subsequent subentries.