Using R to get h5-index for a list of journals

In my last blog post I wrote about impact factors and h-index for different journals. That got me wondering about what the h5 index is for all of the journals that I read and may want to publish in. I could look them all up individually, but that sounds boring and monotonous. I'd much rather figure out how to get R to do it for me. I've never done this kind of thing with R before, so it took a little while, but I wrote a simple function that takes a journal name and returns its h5-index. 

You have to spell the journal's title exactly as it appears in Google Scholar to make sure you get the right h5 index, but otherwise it seems to be reasonably robust. Here it is:

getH5 <- function(journal.name){
  require(RCurl)
  require(XML)
  require(stringr)
  #replace spaces in journal name with "+" for google search
  search.str <- str_replace_all(journal.name, " ", "+")
  #make the URL
url <- paste("http://scholar.google.com/citations?hl=en&view_op=search_venues&vq=", search.str, sep = "")
  #retrieve the webpage from the URL
  webpage <- getURL(url)
  #pull the table of h5 values out of the page
  x <- readHTMLTable(webpage)
  #get the h5-index for the specified journal (there are likely to be other partial matches), use NA if the journal name is not found
  if(length(x)==0){
    h5 <- NA
    warning("Could not find any publications matching ", journal.name, immediate.=T)
  } else {
    tab <- x[[1]]
    h5 <- as.numeric(as.character(tab$"h5-index"[tab$Publication == journal.name]))
    if(length(h5)==0) h5 <- NA
  }
  #arrange in a convenient form
  dat <- data.frame(Journal = journal.name, H5 = h5)
  return(dat)
}

Created by Pretty R at inside-R.org

The function is designed for a single journal name, so for my set of journals, I used the adply function from the plyr package:

jh <- adply(journals, 1, "getH")
jh.sorted <- jh[order(-jh$H5),] #sort them by decreasing h5-index

Created by Pretty R at inside-R.org

After a little clean-up, I got what I was looking for:

Journal	H5
PLoS ONE	120
Nature Neuroscience	115
Brain	103
Trends in Cognitive Sciences	86
Psychological Science	79
Neuropsychologia	67
Journal of Cognitive Neuroscience	64
Psychological Review	62
Cognition	60
Neuroscience Letters	50
Experimental Brain Research	46
The Journal of the Acoustical Society of America	46
Psychonomic Bulletin & Review	45
Journal of Experimental Psychology: General	44
Biological Psychology	44
Journal of Memory and Language	43
Journal of Experimental Psychology: Learning, Memory, and Cognition	43
Journal of Experimental Psychology: Human Perception and Performance	42
Cortex; a journal devoted to the study of the nervous system and behavior	41
Psychology and Aging	41
Brain and Language	39
Brain and Cognition	39
Cognitive Science	38
BMC Neuroscience	38
The Quarterly Journal of Experimental Psychology	36
Ear and Hearing	35
Cognitive Psychology	34
Acta Psychologica	34
Cognitive, Affective, & Behavioral Neuroscience	33
Memory & Cognition	32
Frontiers in Human Neuroscience	29
Attention, Perception, & Psychophysics	28
Language and Cognitive Processes	27
Topics in Cognitive Science	23
Cognitive Neuropsychology	21
Cognitive and Behavioral Neurology	18
Neurocase	18
Cognitive neuroscience	10