bibliometrix (version 4.3.5)

KeywordGrowth: Yearly occurrences of top keywords/terms

Description

It calculates yearly occurrences of top keywords/terms.

Usage

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

Value

an object of class data.frame

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.

Examples

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

# Plotting results
if (FALSE) {
install.packages("reshape2")
library(reshape2)
library(ggplot2)
DF <- melt(topKW, id = "Year")
ggplot(DF, aes(Year, value, group = variable, color = variable)) + geom_line
}