KeywordGrowth function

Yearly occurrences of top keywords/terms

It calculates yearly occurrences of top keywords/terms.

KeywordGrowth(
  M,
  Tag = "ID",
  sep = ";",
  top = 10,
  cdf = TRUE,
  remove.terms = NULL,
  synonyms = NULL
)

Arguments

• M: is a data frame obtained by the converting function convert2df. It is a data matrix with cases corresponding to articles and variables to Field Tag in the original WoS or SCOPUS file.
• Tag: is a character object. It indicates one of the keyword field tags of the standard ISI WoS Field Tag codify (ID or DE) or a field tag created by termExtraction function (TI_TM, AB_TM, etc.).
• sep: is the field separator character. This character separates strings in each keyword column of the data frame. The default is sep = ";".
• top: is a numeric. It indicates the number of top keywords to analyze. The default value is 10.
• cdf: is a logical. If TRUE, the function calculates the cumulative occurrences distribution.
• remove.terms: is a character vector. It contains a list of additional terms to delete from the documents before term extraction. The default is remove.terms = NULL.
• synonyms: is a character vector. Each element contains a list of synonyms, separated by ";", that will be merged into a single term (the first word contained in the vector element). The default is synonyms = NULL.

Returns

an object of class data.frame

Examples

data(scientometrics, package = "bibliometrixData")
topKW=KeywordGrowth(scientometrics, Tag = "ID", sep = ";", top=5, cdf=TRUE)
topKW

# Plotting results
## Not run:

install.packages("reshape2")
library(reshape2)
library(ggplot2)
DF=melt(topKW, id='Year')
ggplot(DF,aes(Year,value, group=variable, color=variable))+geom_line
## End(Not run)