Finding similar bibtex entries

| categories: bibtex, similarity | tags:

A common task while writing scientific papers is citing previous research. I use org-ref extensively for that, and it makes it pretty easy to find similar references, e.g. that have common authors, or common keywords. It also lets me find similar articles in Web of Science or Scopus. Suppose that I have cited a particular paper, e.g. e boes-2016-neural-networ, and I want to find similar references to it that are already in my bibtex file, and similar by my definition. With org-ref I can easily search by keyword or author to find similar entries, but these are limited by what I search for, and they are not sorted. Today, I will explore the first step in a recommender system that calculates similarity, and provides a sorted list of candidates with the most relevant ones first.

The idea is to calculate some measure of similarity between the title of that reference, and the titles of other references in my bibtex file, and then sort them by similarity. This is the reference I want to find similar entries for:

Boes, J. R., Groenenboom, M. C., Keith, J. A., & Kitchin, J. R., Neural network and Reaxff comparison for Au properties, Int. J. Quantum Chem., 116(13), 979–987 (2016). https://doi.org/10.1002/qua.25115

The first thing we do is read in our bibtex file, and print a representative entry.

import bibtexparser
from bibtexparser.bparser import BibTexParser

with open('/Users/jkitchin/Dropbox/bibliography/references.bib') as bibtex_file:
    parser = BibTexParser()
    bib_database = bibtexparser.load(bibtex_file, parser=parser)
    entries = bib_database.entries

print(entries[10])

{'author': 'Jaan Aarik and Aleks Aidla and V{\\"a}ino Sammelselg and Teet\nUustare', 'title': 'Effect of Growth Conditions on Formation of \\ce{TiO_2}-{II}\nThin Films in Atomic Layer Deposition Process', 'journal': 'Journal of Crystal Growth', 'volume': '181', 'number': '3', 'pages': '259 - 264', 'year': '1997', 'doi': '10.1016/S0022-0248(97)00279-0', 'link': 'http://www.sciencedirect.com/science/article/pii/S0022024897002790', 'issn': '0022-0248', 'ENTRYTYPE': 'article', 'ID': 'aarik-1997-effec-growt'}

Each entry is a dictionary containing the fields and their values. For this exploration, I will only consider similarities between titles. The next step is we find which entry corresponds to the reference we want to find similarities to.

ids = [e['ID'] for e in entries]
i = ids.index('boes-2016-neural-networ')
print(entries[i])

{'author': 'Jacob R. Boes and Mitchell C. Groenenboom and John A. Keith\nand John R. Kitchin', 'title': 'Neural Network and {Reaxff} Comparison for {Au} Properties', 'journal': 'Int. J. Quantum Chem.', 'volume': '116', 'number': '13', 'pages': '979-987', 'year': '2016', 'doi': '10.1002/qua.25115', 'link': 'https://doi.org/10.1002/qua.25115', 'issn': '1097-461X', 'keyword': 'Kohn-Sham density functional theory, neural networks, reactive\nforce fields, potential energy surfaces, machine learning', 'ENTRYTYPE': 'article', 'ID': 'boes-2016-neural-networ'}

It is best if we make the entry we want to find similarities to the first one, so here we swap the first and ith entries.

entries[0], entries[i] = entries[i], entries[0]

Now, we prepare the list of strings to get similarities for.

titles = [e.get('title', '') for e in entries]

We will use term frequency–inverse document frequency to get a vector that represents each title, and then use cosine similarity as a measure of similarity. Here is the place to note that I chose these, and could choose other ones too. Also, it is worth noting that in this measure of similarity I did not choose which keywords to measure similarity on.

The functionality for this is provided by sklearn. It has implemented functions for the algorithms above, and in just a few lines of code you get an array of tf-idf features to analyze. The array we get from our vectorizer contains normalized vectors, so we can get the cosine similarity just from a dot product of the vectors. The first row corresponds to the similarity of the first string to all the others. I want them sorted in descending order. The argsort function returns ascending order, so we use a trick to sort the negative of the similarity score which achieves that. There are certainly more advanced treatments of the text we could use by customizing the vectorizer, e.g. word stemming, but for now we neglect that.

from sklearn.feature_extraction.text import TfidfVectorizer

vectorizer = TfidfVectorizer(stop_words='english')
X = vectorizer.fit_transform(titles)

cosine_similarities = (X * X.T).A[0]

related_docs_indices = (-cosine_similarities).argsort()

print('The top 10 recommendations for {} are:\n'.format(S[0]))
for i, j in enumerate(related_docs_indices[1:11]):
    print('{i}. {ID}: {title}, {author}\n'.format(i=i + 1, **entries[j]))

The top 10 recommendations for Neural Network and {Reaxff} Comparison for {Au} Properties are:

  1. behler-2010-neural: Neural network potential-energy surfaces for atomistic

simulations, J{\"o}rg Behler

  1. boes-2017-neural-networ: Neural Network Predictions of Oxygen Interactions on a Dynamic

{Pd} Surface, Jacob R. Boes and John R. Kitchin

  1. eshet-2010-ab: Ab Initio Quality Neural-Network Potential for Sodium, Hagai Eshet and Rustam Z. Khaliullin and Thomas D. K{\"u}hne

and J{\"o}rg Behler and Michele Parrinello

  1. behler-2014-repres-poten: Representing Potential Energy Surfaces By High-Dimensional

Neural Network Potentials, J Behler

  1. behler-2007-gener-neural: Generalized Neural-Network Representation of High-Dimensional

Potential-Energy Surfaces, J{\"o}rg Behler and Michele Parrinello

  1. artrith-2012-high: High-Dimensional Neural Network Potentials for Metal Surfaces:

A Prototype Study for Copper, Nongnuch Artrith and J{\"o}rg Behler

  1. behler-2015-const: Constructing High-Dimensional Neural Network Potentials: A

Tutorial Review, J{\"o}rg Behler

  1. artrith-2011-high: High-Dimensional Neural-Network Potentials for Multicomponent

Systems: Applications To Zinc Oxide, Nongnuch Artrith and Tobias Morawietz and J{\"o}rg Behler

  1. sosso-2012-neural-gete: Neural Network Interatomic Potential for the Phase Change

Material \ce{GeTe}, Gabriele C. Sosso and Giacomo Miceli and Sebastiano Caravati and J{\"o}rg Behler and Marco Bernasconi

  1. lorenz-2006-descr: Descriptions of Surface Chemical Reactions Using a Neural

Network Representation of the Potential-Energy Surface, S{\"o}nke Lorenz and Matthias Scheffler and Axel Gross

It is evident that this is showing other references containing the words "neural network"! I guess that is a little disappointing, since these would just as easily been narrowed down in org-ref. On the other hand, they are sorted and grouped, which would not happen in org-ref. This is a comparison of pretty short strings (just the titles), so maybe this would be much more interesting if abstracts were also included. Including authors would give a different set as well (I tried it, and got a bunch of my own references!).

I don't think it would be very difficult to get this into an Emacs selection tool, e.g. helm/ivy. Check this out:

import pycse.lisp

related_docs_indices[1:6].lisp

'(1592 1650 299 1751 103)'

That is a result that can be read directly by lisp, so we could simply write the code above as a shell script that takes an argument, and returns a list of indices to sort the candidates on. The alternative is to implement this in elisp, perhaps via a dynamic module if there is already a good C library for this. My sense is the Python libraries are more advanced in functionality.

This could have a number of other applications. Given some reference content, you could imagine finding emails that are similar to it, finding RSS entries that are similar to it, finding org headlines that are related, similar files, or similarity with any other set of strings that can be gathered, e.g. from Crossref or some other search, etc. I predict there will be more on these topics in the future!

Copyright (C) 2017 by John Kitchin. See the License for information about copying.

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Org-mode version = 9.0.7

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Automated bibtex entry tweeting

| categories: bibtex, twitter | tags:

The goal in this post is to develop an elisp function that will tweet a bibtex entry. What I want is to be on a bibtex entry, and run a command that will generate a tweet and tweet it. Here is an example bibtex entry I will use in this post. Clearly, I couldn't simply tweet the entry, it is too long. What I want instead is to generate a picture of a formatted citation, to make a gist out of the bibtex entry so we can link to it, and then to provide links in the tweet to the doi, and the bibtex entry gist.

(with-current-buffer (find-file-noselect "~/Dropbox/bibliography/references.bib")
  (goto-char (point-min))
  (re-search-forward "kitchin-2016-autom-data,")
  (bibtex-copy-entry-as-kill)
  (with-temp-buffer
    (bibtex-yank 1)
    (buffer-string)))

First, we tackle making an image. Emacs has some capability to generate svg, and we can readily convert that to png for the tweet. Here we just go to the entry, and then generate a png. I build off the citation capability of org-ref to generate a pretty reasonably formatted entry. It isn't perfect; the volume is missing in the entry, so there is a blank space between two commas, but this is good enough for me. Note we need a png for twitter. It appears you cannot upload svg yet.

(let* ((entry (with-current-buffer (find-file-noselect "~/Dropbox/bibliography/references.bib")
                (goto-char (point-min))
                (re-search-forward "kitchin-2016-autom-data,")
                (bibtex-beginning-of-entry)
                (bibtex-parse-entry t)))
       (formatted-entry (orhc-formatted-citation entry))
       (lines (with-temp-buffer
                (insert formatted-entry)
                (fill-paragraph)
                (split-string  (buffer-string) "\n")))
       (svg (svg-create 500 (* 20 (length lines)))))

  (loop for i from 0
        for line in lines
        do
        (svg-text svg line
                  :font-size "12"
                  :stroke "black"
                  :x 0
                  :y (+ 15 (* i 15))
                  :stroke-width 0.3))

  (with-temp-file "authoring.svg"
    (svg-print svg)))

(shell-command "convert authoring.svg authoring.png")

It is easy enough to get the doi, and generate the url to it.

(let* ((entry (with-current-buffer (find-file-noselect "~/Dropbox/bibliography/references.bib")
                (goto-char (point-min))
                (re-search-forward "kitchin-2016-autom-data,")
                (bibtex-beginning-of-entry)
                (bibtex-parse-entry t))))
  (format "https://doi.org/%s" (cdr (assoc "doi" entry ))))

Next, we will put the entry as a gist on Github, so we can provide a link to it. I use the gist.el package, and here just do some trickery to put the entry in a temp-file named by the key so that the gist has a nice name. This returns the url to the gist, which we would want to incorporate into a tweet.

(with-current-buffer (find-file-noselect "~/Dropbox/bibliography/references.bib")
  (goto-char (point-min))
  (re-search-forward "kitchin-2016-autom-data,")
  (save-restriction
    (bibtex-narrow-to-entry)
    (bibtex-beginning-of-entry)
    (let* ((entry-string (buffer-string))
           (entry (bibtex-parse-entry))
           (key (cdr (assoc "=key=" entry)))
           (tfile (expand-file-name (format "%s.bib" key) temporary-file-directory)))
      (with-temp-file tfile
        (insert entry-string))
      (with-current-buffer (find-file-noselect tfile)
        (gist-buffer)))
    (with-temp-buffer
      (yank)
      (buffer-string))))

Ok, All the pieces are in place. The only piece left is creating the tweet, and tweeting it. I couldn't see an obvious way to do this with twittering mode, since I didn't see where to add an image. There is a Python library for this though, and it looks pretty easy to use. Here is an example usage.

from TwitterAPI import TwitterAPI
from twitter_secrets import CONSUMER_KEY, CONSUMER_SECRET, ACCESS_TOKEN_KEY, ACCESS_TOKEN_SECRET

api = TwitterAPI(CONSUMER_KEY, CONSUMER_SECRET, ACCESS_TOKEN_KEY, ACCESS_TOKEN_SECRET)
file = open('authoring.png', 'rb')
data = file.read()
r = api.request('statuses/update_with_media', {'status':'A test tweet using the TwitterAPI with an image.'}, {'media[]':data})
print(r.status_code)

200

It will be a tad hacky, but the script is so simple we can just make a template, and run it. We need to do these things: 1) make the image, 2) make the gist 3) format and send the tweet. Here is the elisp function to do that.

(defun tweet-bibtex ()
  "Tweet the bibtex entry at point."
  (interactive)
  (bibtex-beginning-of-entry)
  (bibtex-set-field "tweeted" (current-time-string))

  (let* ((entry-string (save-restriction
                         (bibtex-beginning-of-entry)
                         (bibtex-narrow-to-entry)
                         (buffer-substring-no-properties (point-min) (point-max))))
         (entry (bibtex-parse-entry t))
         (key (cdr (assoc "=key=" entry)))
         (doi (cdr (assoc "doi" entry)))
         (svg-file (expand-file-name (format "%s.svg" key) temporary-file-directory))
         (png-file (expand-file-name (format "%s.png" key) temporary-file-directory))
         (bib-file (expand-file-name (format "%s.bib" key) temporary-file-directory))
         (py-file (expand-file-name (format "%s.py" key) temporary-file-directory))
         (formatted-entry (orhc-formatted-citation entry))
         (lines (with-temp-buffer
                  (insert formatted-entry)
                  (fill-paragraph)
                  (split-string  (buffer-string) "\n")))
         (svg (svg-create 500 (* 20 (length lines))))
         (tweet (read-string "Tweet: "))
         gist-url
         full-tweet)

    ;; delete buffers and files
    (loop for buf in (list (concat key ".bib")
                           (concat key ".png")
                           (concat key ".svg")
                           (concat key ".py"))
          do
          (when (get-buffer buf)
            (kill-buffer (get-buffer buf))))

    ;; Step 1 make the image
    (loop for i from 0
          for line in lines
          do
          (svg-text svg line
                    :font-size "12"
                    :stroke "black"
                    :x 0
                    :y (+ 15 (* i 15))
                    :stroke-width 0.3))

    (with-temp-file svg-file
      (svg-print svg))

    (shell-command (format "convert %s %s" svg-file png-file))

    ;; Step 2, make the gist. Make a temp-file so the gist has a reasonable name
    (with-temp-file bib-file
      (insert entry-string))

    (let ((bib-buffer (find-file-noselect bib-file)))
      (with-current-buffer bib-buffer
        (gist-buffer))
      (kill-buffer bib-buffer))

    ;; get url off clipboard
    (setq gist-url (with-temp-buffer
                     (yank)
                     (buffer-string)))

    ;; Format and send the tweet:
    (setq full-tweet (format "#publication %s\nhttps://doi.org/%s\nbibtex: %s" tweet doi gist-url))

    (with-temp-file py-file
      (insert (format "from TwitterAPI import TwitterAPI
from twitter_secrets import CONSUMER_KEY, CONSUMER_SECRET, ACCESS_TOKEN_KEY, ACCESS_TOKEN_SECRET

api = TwitterAPI(CONSUMER_KEY, CONSUMER_SECRET, ACCESS_TOKEN_KEY, ACCESS_TOKEN_SECRET)
file = open('%s', 'rb')
data = file.read()
r = api.request('statuses/update_with_media', {'status':'''%s'''}, {'media[]':data})"
                      png-file
                      full-tweet)))

    (if (= 0 (shell-command (format "python %s" py-file)))
        (message "%s" full-tweet)
      (message "tweet failed ;("))))

;; Now, try it out.
(with-current-buffer (find-file-noselect "~/Dropbox/bibliography/references.bib")
  (goto-char (point-min))
  (re-search-forward "kitchin-2016-autom-data,")
  (tweet-bibtex))

You can see what this tweet looks like here:

That seems pretty reasonable. Now I only need to use it about 48,000 times to benefit from the time-savings M-x tweet-bibtex offers compared to manually making all those tweets ;)

Copyright (C) 2016 by John Kitchin. See the License for information about copying.

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Org-mode version = 8.3.4

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A python version of the s-exp bibtex entry

| categories: bibtex, ref, python | tags:

In this post we explored representing a bibtex entry in lisp s-exp notation, and showed interesting things that enables. Here, I explore something similar in Python. The s-exp notation in Python is really more like tuples. It looks almost identical, except we need a lot of commas for the Python syntax. One significant difference in Python is we need to define the functions in advance because otherwise the function symbols are undefined. Similar to lisp, we can define the field functions at run-time in a loop. We have to use an eval statement, which some Pythonistas find distasteful, but it is not that different to me than what we did in lisp.

The syntax for "executing" the data structure is quite different than in lisp, because this data is not code in Python. Instead, we have to deconstruct the data, knowing that the function is the first object, and it takes the remaining arguments in the tuple.

Here is the proof of concept:

def article(bibtex_key, *args):
    "Return the bibtex formatted entry"
    return ',\n'.join(['@article{{{0}}}'.format(bibtex_key)] +[arg[0](arg[1]) for arg in args[0]] + ['}'])

fields = ("author", "title", "journal", "pages", "number", "doi", "url", "eprint", "year")

for f in fields:
    locals()[f] = eval ('lambda x: "  {0} = {{{1}}}".format("' + f + '", x)')

entry = (article, "hallenbeck-2013-effec-o2",
         (author, "Hallenbeck, Alexander P. and Kitchin, John R."),
         (title, "Effects of \ce{O_2} and \ce{SO_2} on the capture capacity of a primary-amine based polymeric \ce{CO_2} sorbent"),
         (journal, "Industrial \& Engineering Chemistry Research"),
         (pages, "10788-10794"),
         (year, 2013),
         (number, 31),
         (doi, "10.1021/ie400582a"),
         (url, "http://pubs.acs.org/doi/abs/10.1021/ie400582a"),
         (eprint, "http://pubs.acs.org/doi/pdf/10.1021/ie400582a"))


print entry[0](entry[1], entry[2:])
@article{hallenbeck-2013-effec-o2},
  author = {Hallenbeck, Alexander P. and Kitchin, John R.},
  title = {Effects of \ce{O_2} and \ce{SO_2} on the capture capacity of a primary-amine based polymeric \ce{CO_2} sorbent},
  journal = {Industrial \& Engineering Chemistry Research},
  pages = {10788-10794},
  year = {2013},
  number = {31},
  doi = {10.1021/ie400582a},
  url = {http://pubs.acs.org/doi/abs/10.1021/ie400582a},
  eprint = {http://pubs.acs.org/doi/pdf/10.1021/ie400582a},
}

We can still get specific fields out. Since we used a tuple here, it is not quite as nice as using a dictionary, but it is neither too bad, and it can be wrapped in a reasonably convenient function.

def article(bibtex_key, *args):
    "Return the bibtex formatted entry"
    return ',\n'.join(['@article{{{0}}}'.format(bibtex_key)] +[arg[0](arg[1]) for arg in args[0]] + ['}'])

fields = ("author", "title", "journal", "pages", "number", "doi", "url", "eprint", "year")

for f in fields:
    locals()[f] = eval ('lambda x: "  {0} = {{{1}}}".format("' + f + '", x)')

entry = (article, "hallenbeck-2013-effec-o2",
         (author, "Hallenbeck, Alexander P. and Kitchin, John R."),
         (title, "Effects of \ce{O_2} and \ce{SO_2} on the capture capacity of a primary-amine based polymeric \ce{CO_2} sorbent"),
         (journal, "Industrial \& Engineering Chemistry Research"),
         (pages, "10788-10794"),
         (year, 2013),
         (number, 31),
         (doi, "10.1021/ie400582a"),
         (url, "http://pubs.acs.org/doi/abs/10.1021/ie400582a"),
         (eprint, "http://pubs.acs.org/doi/pdf/10.1021/ie400582a"))


for field in entry[2:]:
    if field[0] == author:
        print field

def get_field(entry, field):
    for element in entry[2:]:
        if element[0] == field:
            return element[1]
    else:
        return None

print get_field(entry, title)
print get_field(entry, "bad")
(<function <lambda> at 0x1005975f0>, 'Hallenbeck, Alexander P. and Kitchin, John R.')
Effects of \ce{O_2} and \ce{SO_2} on the capture capacity of a primary-amine based polymeric \ce{CO_2} sorbent
None

So, it seems Python can do some things like lisp in treating functions like first-class objects that can be used as functions, or keys. I still like the lisp s-exp better, but this is an interesting idea for Python too.

Copyright (C) 2015 by John Kitchin. See the License for information about copying.

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Org-mode version = 8.2.10

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A sexp version of a bibtex entry

| categories: bibtex, lisp | tags:

Below you see a typical bibtex entry. Today we explore an alternate approach to represent the information (data) in that entry as s-expressions, i.e. as a lisp data structure. Why? because it seems like an interesting exploration!

@article{hallenbeck-2013-effec-o2,
  author =       "Hallenbeck, Alexander P. and Kitchin, John R.",
  title =        {Effects of \ce{O_2} and \ce{SO_2} on the capture capacity of a
                  primary-amine based polymeric \ce{CO_2} sorbent},
  keywords =     {RUA, orgmode},
  journal =      "Industrial \& Engineering Chemistry Research",
  pages =        "10788-10794",
  year =         2013,
  volume =       {52},
  number =       {31},
  doi =          "10.1021/ie400582a",
  url =          "http://pubs.acs.org/doi/abs/10.1021/ie400582a",
  eprint =       "http://pubs.acs.org/doi/pdf/10.1021/ie400582a",
}

Here is what that same data structure might look like as a sexp-based lisp data structure.

(article "hallenbeck-2013-effec-o2"
         (author "Hallenbeck, Alexander P. and Kitchin, John R.")
         (title "Effects of \ce{O_2} and \ce{SO_2} on the capture capacity of a primary-amine based polymeric \ce{CO_2} sorbent")
         (journal "Industrial \& Engineering Chemistry Research")
         (pages "10788-10794")
         (year 2013)
         (number 31)
         (doi "10.1021/ie400582a")
         (url "http://pubs.acs.org/doi/abs/10.1021/ie400582a")
         (eprint "http://pubs.acs.org/doi/pdf/10.1021/ie400582a"))

We can retrieve data from the sexp form pretty easily. Here we get the authors.

(let* ((art '(article "hallenbeck-2013-effec-o2"
                      (author "Hallenbeck, Alexander P. and Kitchin, John R.")
                      (title "Effects of \ce{O_2} and \ce{SO_2} on the capture capacity of a primary-amine based polymeric \ce{CO_2} sorbent")
                      (journal "Industrial \& Engineering Chemistry Research")
                      (pages "10788-10794")
                      (year 2013)
                      (number 31)
                      (doi "10.1021/ie400582a")
                      (url "http://pubs.acs.org/doi/abs/10.1021/ie400582a")
                      (eprint "http://pubs.acs.org/doi/pdf/10.1021/ie400582a")))
       (fields (cddr art)))
  (cadr (assoc 'author fields)))
Hallenbeck, Alexander P. and Kitchin, John R.

That is simple enough you might just write a little function to streamline it like this, and return a formatted string.

(defun get-article-field (article field)
  "Return value of FIELD in ARTICLE."
  (cadr (assoc field (cddr article))))

(let ((art '(article "hallenbeck-2013-effec-o2"
                     (author "Hallenbeck, Alexander P. and Kitchin, John R.")
                     (title "Effects of \ce{O_2} and \ce{SO_2} on the capture capacity of a primary-amine based polymeric \ce{CO_2} sorbent")
                     (journal "Industrial \& Engineering Chemistry Research")
                     (pages "10788-10794")
                     (year 2013)
                     (number 31)
                     (doi "10.1021/ie400582a")
                     (url "http://pubs.acs.org/doi/abs/10.1021/ie400582a")
                     (eprint "http://pubs.acs.org/doi/pdf/10.1021/ie400582a"))))
  (format "%s, doi:%s (%s)"
          (get-article-field art 'author)
          (get-article-field art 'doi)
          (get-article-field art 'year)))
Hallenbeck, Alexander P. and Kitchin, John R., doi:10.1021/ie400582a (2013)

You might be wondering, why is that even a little bit interesting? One reason is that it looks a little like what lisp returns after parsing an xml file. Another is, the data structure looks kind of like data, but it is also some code, if article was defined as a function! Let us consider what this might look like. I use a macro to define the field functions since in this case they all do the same thing, and these simply return a string with the field-name and value in curly brackets. We eval the macro to make sure it defines the function. I define an article function that wraps the fields in @bibtex-key{fields}, which defines a bibtex entry.

(defmacro make-field (field-name)
  "define a field that returns a string"
  `(defun ,(intern field-name) (content)
     (format "  %s = {%s}" ,field-name content)))

(loop for field in '("author" "title" "journal" "pages" "number" "doi" "url" "eprint" "year")
  do (eval `(make-field ,field)))

(defun article (bibtex-key &rest fields)
  (concat
   (format "@article{%s,\n" bibtex-key)
   (mapconcat (lambda (field) (eval field)) fields ",\n")
   "\n}\n"))

(article "hallenbeck-2013-effec-o2"
         (author "Hallenbeck, Alexander P. and Kitchin, John R.")
         (title "Effects of \ce{O_2} and \ce{SO_2} on the capture capacity of a primary-amine based polymeric \ce{CO_2} sorbent")
         (journal "Industrial \& Engineering Chemistry Research")
         (pages "10788-10794")
         (number 31)
         (year 2013)
         (doi "10.1021/ie400582a")
         (url "http://pubs.acs.org/doi/abs/10.1021/ie400582a")
         (eprint "http://pubs.acs.org/doi/pdf/10.1021/ie400582a"))
@article{hallenbeck-2013-effec-o2,
  author = {Hallenbeck, Alexander P. and Kitchin, John R.},
  title = {Effects of ce{O_2} and ce{SO_2} on the capture capacity of a primary-amine based polymeric ce{CO_2} sorbent},
  journal = {Industrial & Engineering Chemistry Research},
  pages = {10788-10794},
  number = {31},
  year = {2013},
  doi = {10.1021/ie400582a},
  url = {http://pubs.acs.org/doi/abs/10.1021/ie400582a},
  eprint = {http://pubs.acs.org/doi/pdf/10.1021/ie400582a}
}

Wow. We executed our data structure, and got a bibtex entry! That seems moderately interesting to me. Next is an example of taking the same data structure and rendering it as xml. This is some lispy wizardry, rather than use a macro to define functions, I temporarily define functions within a cl-flet macro, which I have to collect as a list of code. Then, I eval the list. This feels pretty odd, but seems like a lispy kind of thing to do.

(eval
 (list 'cl-flet
       (append (loop for field in '("author" "title" "journal" "pages"
                                      "number" "doi" "url" "eprint" "year")
                       collect (list (intern field)
                                     '(content)
                                     `(format "  <%s>%s</%s>" ,field content ,field)))
               '((article (bibtex-key &rest fields)
                          (concat
                           (format
                            "<article bibtex-key=\"%s\">\n" bibtex-key)
                           (mapconcat (lambda (field) (eval field)) fields "\n")
                           "\n</article>")))
               )
       ;; body of cl-flet
       '(article "hallenbeck-2013-effec-o2"
                (author "Hallenbeck, Alexander P. and Kitchin, John R.")
                (title "Effects of \ce{O_2} and \ce{SO_2} on the capture capacity of a primary-amine based polymeric \ce{CO_2} sorbent")
                (journal "Industrial \& Engineering Chemistry Research")
                (pages "10788-10794")
                (number 31)
                (year 2013)
                (doi "10.1021/ie400582a")
                (url "http://pubs.acs.org/doi/abs/10.1021/ie400582a")
                (eprint "http://pubs.acs.org/doi/pdf/10.1021/ie400582a"))))
<article bibtex-key="hallenbeck-2013-effec-o2">
  <author>Hallenbeck, Alexander P. and Kitchin, John R.</author>
  <title>Effects of ce{O_2} and ce{SO_2} on the capture capacity of a primary-amine based polymeric ce{CO_2} sorbent</title>
  <journal>Industrial & Engineering Chemistry Research</journal>
  <pages>10788-10794</pages>
  <number>31</number>
  <year>2013</year>
  <doi>10.1021/ie400582a</doi>
  <url>http://pubs.acs.org/doi/abs/10.1021/ie400582a</url>
  <eprint>http://pubs.acs.org/doi/pdf/10.1021/ie400582a</eprint>
</article>

Prefer json? No problem, just reformat the functions!

(eval
 (list 'cl-flet
       (append (loop for field in '("author" "title" "journal" "pages"
                                      "number" "doi" "url" "eprint" "year")
                       collect (list (intern field)
                                     '(content)
                                     `(format "   \"%s\": \"%s\"" ,field content)))
               '((article (bibtex-key &rest fields)
                          (concat
                           (format
                            "{\"article\":\n  {\"bibtex-key\": \"%s\",\n" bibtex-key)
                           (mapconcat (lambda (field) (eval field)) fields ",\n")
                           "}\n}"))))
       ;; body of cl-flet
       '(article "hallenbeck-2013-effec-o2"
                (author "Hallenbeck, Alexander P. and Kitchin, John R.")
                (title "Effects of \ce{O_2} and \ce{SO_2} on the capture capacity of a primary-amine based polymeric \ce{CO_2} sorbent")
                (journal "Industrial \& Engineering Chemistry Research")
                (pages "10788-10794")
                (number 31)
                (year 2013)
                (doi "10.1021/ie400582a")
                (url "http://pubs.acs.org/doi/abs/10.1021/ie400582a")
                (eprint "http://pubs.acs.org/doi/pdf/10.1021/ie400582a"))))
{"article":
  {"bibtex-key": "hallenbeck-2013-effec-o2",
   "author": "Hallenbeck, Alexander P. and Kitchin, John R.",
   "title": "Effects of ce{O_2} and ce{SO_2} on the capture capacity of a primary-amine based polymeric ce{CO_2} sorbent",
   "journal": "Industrial & Engineering Chemistry Research",
   "pages": "10788-10794",
   "number": "31",
   "year": "2013",
   "doi": "10.1021/ie400582a",
   "url": "http://pubs.acs.org/doi/abs/10.1021/ie400582a",
   "eprint": "http://pubs.acs.org/doi/pdf/10.1021/ie400582a"}
}

Is this useful? Great question. I don't plan to convert by bibtex files to sexp format anytime soon ;) The format I used above is just a simple one. It might be desirable to include individual authors instead of an author string, and maybe support attributes to establish an author order. An author structure might be more complex to include scientific ids like an orcid, alternative names, etc… Finally, the s-exp data structure is super easy to use in lisp, but other languages would have parse it into some native structure the way they parse json or xml. There is limited support for s-expressions in most other non-lispy languages.

I like the idea of data representation as code, and its conversion to some other kind of format. It is subtle here, but notice we never had to write a parser for the sexp notation. That already exists as the lisp interpreter. We did write code to use the data, and convert the data. The sexp notation is pretty easy to write, in contrast to the xml or json representations. Some interesting issues might be what to do with fields that are not defined, perhaps a macro would be used on the fly, or in the cl-flet definition. It is hard to imagine doing these things in another language than lisp!

Copyright (C) 2015 by John Kitchin. See the License for information about copying.

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Bibtex Entries from Arxiv.org

| categories: bibtex, emacs | tags:

http://arxiv.org is an open-source physics preprint server where copies of scientific manuscripts can be found. For example, http://arxiv.org/abs/0801.1144 is a paper I wrote, and you can find the PDF for that paper here: http://arxiv.org/pdf/0801.1144v1 . Each entry at Arxiv has an arxiv number, and for this paper the number is "0801.1144". In this post, we explore some capabilities of the arxiv.el library which is part of org-ref (https://github.com/jkitchin/org-ref ).

To use this library, get the org-ref distribution, make sure it is on your path, and then require the library:

(require 'arxiv)

First, there is a new org-link: arxiv:0801.1144. This is a clickable link that simply opens arxiv.org at the URL for an arxiv number, and exports as a link to that entry in arxiv.

On the right hand side of the arxiv page, there is a link under References & Citations that takes you to a page where you can get a bibtex entry. The link for this entry is http://adsabs.harvard.edu/cgi-bin/bib_query?arXiv:0801.1144 . On that page, there is a link to a bibtex entry (http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2008PhRvB..77g5437K&data_type=BIBTEX&db_key=PHY&nocookieset=1 ). We can construct this link pretty easily, we just need the bibcode for that entry. arxiv.el provides a function for that.

(arxiv-get-bibliographic-code "0801.1144")
2008PhRvB..77g5437K

Next, once we have a url, we can get the text of the bibtex entry.

(arxiv-get-bibtex-entry "2008PhRvB..77g5437K")
@ARTICLE{2008PhRvB..77g5437K,
   author = {{Kitchin}, J.~R. and {Reuter}, K. and {Scheffler}, M.},
    title = "{Alloy surface segregation in reactive environments: First-principles atomistic thermodynamics study of Ag$_{3}$Pd(111) in oxygen atmospheres}",
  journal = {\prb},
archivePrefix = "arXiv",
   eprint = {0801.1144},
 primaryClass = "cond-mat.mtrl-sci",
 keywords = {Ab initio calculations of adsorbate structure and reactions, Density functional theory local density approximation gradient and other corrections, Oxidation},
     year = 2008,
    month = feb,
   volume = 77,
   number = 7,
      eid = {075437},
    pages = {075437},
      doi = {10.1103/PhysRevB.77.075437},
   adsurl = {http://adsabs.harvard.edu/abs/2008PhRvB..77g5437K},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}

Finally, arxiv.el wraps those to functions together into an interactive function arxiv-add-bibtex-entry which prompts you for an arxiv number, and then a bibtex file, and then adds the text above to your bibtex file. You can then clean the entry as you see fit. It is also possible to get the pdf for an arxiv entry via arxiv-get-pdf. This is an interactive function that will prompt you for an arxiv number and a pdf file name, and it will then get the pdf for you and open it. I have not integrated this with the bibtex entry function yet, but one would ideally clean the bibtex entry to get a uniform key, and then get the pdf and name it according to the key like we do in org-ref.

(arxiv-get-pdf "0801.1144" "0801.1144.pdf")

If you use words.el you will find a new function words-arxiv which allows you to search the selected text or word at point on arxiv.org.

I do not use arxiv.org a lot, so this is not super well tested on many articles in arxiv.org, but it has worked on the few examples I have tested so far.

Copyright (C) 2015 by John Kitchin. See the License for information about copying.

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