Introduction to rplos

Scott Chamberlain

2020-04-07

The rplos package interacts with the API services of PLoS (Public Library of Science) Journals. You used to need an API key to work with this package - that is no longer needed!

This tutorial will go through three use cases to demonstrate the kinds of things possible in rplos.

Load package from CRAN

install.packages("rplos")
library('rplos')

Search across PLoS papers in various sections of papers

searchplos is a general search, and in this case searches for the term Helianthus and returns the DOI’s of matching papers

searchplos(q = "Helianthus", fl = "id", limit = 5)
#> $meta
#> # A tibble: 1 x 2
#>   numFound start
#>      <int> <int>
#> 1      608     0
#> 
#> $data
#> # A tibble: 5 x 1
#>   id                          
#>   <chr>                       
#> 1 10.1371/journal.pone.0198869
#> 2 10.1371/journal.pone.0213065
#> 3 10.1371/journal.pone.0148280
#> 4 10.1371/journal.pone.0111982
#> 5 10.1371/journal.pone.0212371

Get only full article DOIs

searchplos(q = "*:*", fl = 'id', fq = 'doc_type:full', start = 0, limit = 5)
#> $meta
#> # A tibble: 1 x 2
#>   numFound start
#>      <int> <int>
#> 1   273907     0
#> 
#> $data
#> # A tibble: 5 x 1
#>   id                          
#>   <chr>                       
#> 1 10.1371/journal.pone.0020843
#> 2 10.1371/journal.pone.0022257
#> 3 10.1371/journal.pone.0023139
#> 4 10.1371/journal.pone.0023138
#> 5 10.1371/journal.pone.0023119

Get DOIs for only PLoS One articles

searchplos(q = "*:*", fl = 'id', fq = 'journal_key:PLoSONE',
           start = 0, limit = 5)
#> $meta
#> # A tibble: 1 x 2
#>   numFound start
#>      <int> <int>
#> 1  2001428     0
#> 
#> $data
#> # A tibble: 5 x 1
#>   id                          
#>   <chr>                       
#> 1 10.1371/journal.pone.0020843
#> 2 10.1371/journal.pone.0022257
#> 3 10.1371/journal.pone.0023139
#> 4 10.1371/journal.pone.0023138
#> 5 10.1371/journal.pone.0023119

Get DOIs for full article in PLoS One

searchplos(q = "*:*", fl = 'id',
   fq = list('journal_key:PLoSONE', 'doc_type:full'),
   start = 0, limit = 5)
#> $meta
#> # A tibble: 1 x 2
#>   numFound start
#>      <int> <int>
#> 1   231685     0
#> 
#> $data
#> # A tibble: 5 x 1
#>   id                          
#>   <chr>                       
#> 1 10.1371/journal.pone.0020843
#> 2 10.1371/journal.pone.0022257
#> 3 10.1371/journal.pone.0023139
#> 4 10.1371/journal.pone.0023138
#> 5 10.1371/journal.pone.0023119

Search for many terms

q <- c('ecology','evolution','science')
lapply(q, function(x) searchplos(x, limit = 2))
#> [[1]]
#> [[1]]$meta
#> # A tibble: 1 x 2
#>   numFound start
#>      <int> <int>
#> 1    51686     0
#> 
#> [[1]]$data
#> # A tibble: 2 x 1
#>   id                          
#>   <chr>                       
#> 1 10.1371/journal.pone.0001248
#> 2 10.1371/journal.pone.0059813
#> 
#> 
#> [[2]]
#> [[2]]$meta
#> # A tibble: 1 x 2
#>   numFound start
#>      <int> <int>
#> 1    77101     0
#> 
#> [[2]]$data
#> # A tibble: 2 x 1
#>   id                          
#>   <chr>                       
#> 1 10.1371/journal.pbio.2002255
#> 2 10.1371/journal.pone.0205798
#> 
#> 
#> [[3]]
#> [[3]]$meta
#> # A tibble: 1 x 2
#>   numFound start
#>      <int> <int>
#> 1   241863     0
#> 
#> [[3]]$data
#> # A tibble: 2 x 1
#>   id                          
#>   <chr>                       
#> 1 10.1371/journal.pone.0229237
#> 2 10.1371/journal.pone.0202320

Search on specific sections

A suite of functions were created as light wrappers around searchplos as a shorthand to search specific sections of a paper.

plosauthor searches across authors, and in this case returns the authors of the matching papers. the fl parameter determines what is returned

plosauthor(q = "Eisen", fl = "author", limit = 5)
#> $meta
#> # A tibble: 1 x 2
#>   numFound start
#>      <int> <int>
#> 1     1077     0
#> 
#> $data
#> # A tibble: 5 x 1
#>   author                                                                       
#>   <chr>                                                                        
#> 1 Myungsun Kang,Timothy J Eisen,Ellen A Eisen,Arup K Chakraborty,Herman N Eisen
#> 2 Myungsun Kang,Timothy J Eisen,Ellen A Eisen,Arup K Chakraborty,Herman N Eisen
#> 3 Myungsun Kang,Timothy J Eisen,Ellen A Eisen,Arup K Chakraborty,Herman N Eisen
#> 4 Myungsun Kang,Timothy J Eisen,Ellen A Eisen,Arup K Chakraborty,Herman N Eisen
#> 5 Myungsun Kang,Timothy J Eisen,Ellen A Eisen,Arup K Chakraborty,Herman N Eisen

plosabstract searches across abstracts, and in this case returns the id and title of the matching papers

plosabstract(q = 'drosophila', fl = 'id,title', limit = 5)
#> $meta
#> # A tibble: 1 x 2
#>   numFound start
#>      <int> <int>
#> 1     3788     0
#> 
#> $data
#> # A tibble: 5 x 2
#>   id                     title                                                  
#>   <chr>                  <chr>                                                  
#> 1 10.1371/journal.pone.… "Host Range and Specificity of the Drosophila C Virus" 
#> 2 10.1371/journal.pone.… "Exogenous expression of Drp1 plays neuroprotective ro…
#> 3 10.1371/journal.pone.… "A Drosophila model for developmental nicotine exposur…
#> 4 10.1371/image.pbio.v0… "PLoS Biology Issue Image | Vol. 6(5) May 2008"        
#> 5 10.1371/journal.pone.… "Larval Defense against Attack from Parasitoid Wasps R…

plostitle searches across titles, and in this case returns the title and journal of the matching papers

plostitle(q = 'drosophila', fl = 'title,journal', limit = 5)
#> $meta
#> # A tibble: 1 x 2
#>   numFound start
#>      <int> <int>
#> 1     2397     0
#> 
#> $data
#> # A tibble: 5 x 2
#>   journal  title                                                                
#>   <chr>    <chr>                                                                
#> 1 PLOS ONE Tandem Duplications and the Limits of Natural Selection in Drosophil…
#> 2 PLoS ONE A DNA Virus of Drosophila                                            
#> 3 PLOS ONE Peptidergic control in a fruit crop pest: The spotted-wing drosophil…
#> 4 PLOS ONE Nematocytes: Discovery and characterization of a novel anculeate hem…
#> 5 PLoS ONE In Vivo RNAi Rescue in Drosophila melanogaster with Genomic Transgen…

Search terms & visualize results as a histogram OR as a plot through time

plosword allows you to search for 1 to K words and visualize the results as a histogram, comparing number of matching papers for each word

out <- plosword(list("monkey", "Helianthus", "sunflower", "protein", "whale"),
    vis = "TRUE")
out$table
#>   No_Articles       Term
#> 1       13867     monkey
#> 2         608 Helianthus
#> 3        1759  sunflower
#> 4      156937    protein
#> 5        2001      whale
out$plot

plot of chunk plosword1plot

You can also pass in curl options, in this case get verbose information on the curl call.

plosword('Helianthus', callopts = list(verbose = TRUE))
#> Number of articles with search term 
#>                                 608

Visualize terms

plot_throughtime allows you to search for up to 2 words and visualize the results as a line plot through time, comparing number of articles matching through time. Visualize with the ggplot2 package, only up to two terms for now.

library("ggplot2")
plot_throughtime(terms = "phylogeny", limit = 200) +
  geom_line(size = 2, color = 'black')

plot of chunk throughtime1

More

See the Faceted and highlighted searches and Full text vignettes for more rplos help.