utils::globalVariables(c("AU", "n", "TC", "PY", "AU.x", "year", "Author",
"TCpY", "freq"))
#' Top-Authors' Productivity over Time
#'
#' It calculates and plots the author production (in terms of number of publications) over the time.
#' @param M is a bibliographic data frame obtained by \code{\link{convert2df}} function.
#' @param k is a integer. It is the number of top authors to analyze and plot. Default is \code{k = 10}.
#' @param graph is logical. If TRUE the function plots the author production over time graph. Default is \code{graph = TRUE}.
#' @return The function \code{authorProdOverTime} returns a list containing two objects:
#' \tabular{lll}{
#' \code{dfAU} \tab \tab is a data frame\cr
#' \code{dfpapersAU}\tab \tab is a data frame\cr
#' \code{graph} \tab \tab a ggplot object}
#'
#' @examples
#' data(scientometrics, package = "bibliometrixData")
#' res <- authorProdOverTime(scientometrics, k=10)
#' print(res$dfAU)
#' plot(res$graph)
#'
#' @seealso \code{\link{biblioAnalysis}} function for bibliometric analysis
#' @seealso \code{\link{summary}} method for class '\code{bibliometrix}'
#'
#' @export
#'
authorProdOverTime <- function(M,k=10, graph=TRUE){
if (!("DI" %in% names(M))){M$DI="NA"}
M$TC <- as.numeric(M$TC)
M$PY <- as.numeric(M$PY)
M <- M[!is.na(M$PY),] #remove rows with missing value in PY
Y <- as.numeric(substr(Sys.time(),1,4))
listAU <- (strsplit(M$AU, ";"))
nAU <- lengths(listAU)
df <- data.frame(AU=trimws(unlist(listAU)), SR=rep(M$SR,nAU))
AU <- df %>%
group_by(AU) %>%
count() %>%
arrange(desc(n)) %>%
ungroup()
k <- min(k,nrow(AU))
AU <- AU %>%
slice_head(n=k)
df <- df %>%
right_join(AU, by = "AU") %>%
left_join(M, by = "SR") %>%
select("AU.x","PY","TI","SO","DI","TC") %>%
mutate(TCpY = TC/(Y-PY+1)) %>%
group_by(AU.x) %>%
mutate(n = length(AU.x)) %>%
ungroup() %>%
rename(Author = AU.x,
year = PY,
DOI = DI) %>%
arrange(desc(n), desc(year)) %>%
select(-n)
df2 <- dplyr::group_by(df, Author,year) %>%
dplyr::summarise(freq=length(year),TC=sum(TC),TCpY=sum(TCpY)) %>%
as.data.frame()
df2$Author <- factor(df2$Author,levels=AU$AU[1:k])
x <- c(0.5,1.5*k/10)
y <- c(min(df$year),min(df$year)+diff(range(df2$year))*0.125)
data("logo",envir=environment())
logo <- grid::rasterGrob(logo,interpolate = TRUE)
g <- ggplot(df2, aes(x=Author, y=year, text = paste("Author: ", Author,"\nYear: ",year ,"\nN. of Articles: ",freq ,"\nTotal Citations per Year: ", round(TCpY,2))))+
geom_point(aes(alpha=TCpY,size = freq), color="dodgerblue4")+
scale_size(range=c(2,6))+
scale_alpha(range=c(0.3,1))+
scale_y_continuous(breaks = seq(min(df2$year),max(df2$year), by=2))+
guides(size = guide_legend(order = 1, "N.Articles"), alpha = guide_legend(order = 2, "TC per Year"))+
theme(legend.position = 'right'
,text = element_text(color = "#444444")
,panel.background = element_rect(fill = '#FFFFFF')
,plot.title = element_text(size = 24)
,axis.title = element_text(size = 14, color = '#555555')
,axis.title.y = element_text(vjust = 1, angle = 90)#, face="bold")
,axis.title.x = element_text(hjust = .95)#,face="bold")
,axis.text.x = element_text(face="bold", angle = 90)
,axis.text.y = element_text(face="bold")
#,axis.line.x = element_line(color="black", size=1)
,axis.line.x = element_line(color="grey50", linewidth=0.5)
,panel.grid.major.x = element_blank()
,panel.grid.major.y = element_line( linewidth=.2, color="grey90" )
)+
#coord_fixed(ratio = 2/1) +
labs(title="Authors' Production over Time",
x="Author",
y="Year")+
geom_line(data=df2,aes(x = Author, y = year, group=Author),size=1.0, color="firebrick4", alpha=0.3 )+
scale_x_discrete(limits = rev(levels(df2$Author)))+
coord_flip() +
annotation_custom(logo, xmin = x[1], xmax = x[2], ymin = y[1], ymax = y[2])
df$DOI=as.character(df$DOI)
res <- list(dfAU=df2,dfPapersAU=df,graph=g)
if (isTRUE(graph)){plot(g)}
return(res)
}
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.