The function fieldByYear returns a list containing threeobjects:
df
is a data frame
df_graph
is a data frame with data used to build the graph
graph
a ggplot object
Arguments
M
is a bibliographic data frame obtained by convert2df function.
field
is a character object. It indicates one of the field tags of the
standard ISI WoS Field Tag codify.
timespan
is a vector with the min and max year. If it is = NULL, the analysis is performed on the entire period. Default is timespan = NULL.
min.freq
is an integer. It indicates the min frequency of the items to include in the analysis
n.items
is an integer. I indicates the maximum number of items per year to include in the plot.
labelsize
is deprecated argument. It will be removed in the next update.
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.
dynamic.plot
is a logical. If TRUE plot aesthetics are optimized for plotly package.
graph
is logical. If TRUE the function plots Filed Tag distribution by Year graph. Default is graph = TRUE.