====== JCR ======

<code>
https://github.com/bavla/Rnet

https://figshare.com/authors/Loet_Leydesdorff/684994  
https://www.leydesdorff.net/
https://documenter.getpostman.com/view/7840038/SzYaVdeo?version=latest


https://www.leydesdorff.net/jcr07/cited/

https://www.aminer.org/citation
https://www.citnetexplorer.nl/
https://harzing.com/resources/publish-or-perish
https://linqs.soe.ucsc.edu/data

https://www.slideshare.net/MasoudMohammadi5/citation-analysis-85720471
https://github.com/rcsb/BioCaddiePilot32/blob/master/src/main/resources/NetworkAnalysis.md
https://www.bibliometrix.org/
https://networkrepository.com/cit.php

</code>

===== Combining JCR networks into a single network for each year =====


Combine networks from  https://www.leydesdorff.net/jcr07/cited/   into a single network for each year. 

At the first sight it seems that the files are numbered with consecutive numbers. But it turned out that this assumption doesn't hold. 
<code>
<b>Cited 2007:</b><br>
<A HREF="v1.txt">Aapg Bulletin</A><BR>
<A HREF="v2.txt">Aaps Journal</A><BR>
<A HREF="v3.txt">Aaps Pharmscitech</A><BR>
<A HREF="v4.txt">Aatcc Review</A><BR>
<A HREF="v10001.txt">Abacus A Journal Of Accounting Finance And Business Studies</A><BR>
<A HREF="v5.txt">Abdominal Imaging</A><BR>
...
<A HREF="v6416.txt">Zuckerindustrie</A><BR>
<A HREF="v11865.txt">Zygon</A><BR>
<A HREF="v6417.txt">Zygote</A><BR>
</code>
I cut-out from the html description of the page https://www.leydesdorff.net/jcr07/cited/ the list of all files and saved it in the file ''list07.txt''. From it I extracted in R the corresponding file names.
<code>
> wdir <- "C:/Users/vlado/work2/data/nets/loet"
> setwd(wdir)
> source("Pajek.R")
>
> # https://www.leydesdorff.net/jcr07/cited/v4.txt
>
> cat("Start:",format(Sys.time(), "%H:%M:%S"),"\n") 
> durl <- "https://www.leydesdorff.net/jcr07/cited/"
> L <- readLines("list07.txt"); L <- L[tolower(substr(L,1,2))=="<a"]
> S <- unlist(strsplit(L,'"')); F <- tolower(S[3*(1:length(L))-1])
> m <- 0; mmax <- 800000; ner <- 0
> U <- rep(NA,mmax); V <- rep(NA,mmax); W <- rep(NA,mmax)
> N <- c(); N["§{@@@@@@@@}§"] <- 0; j <- 0
> for(f in F){
+   j <- j+1
+   if(j %% 100==0) {cat(j,":",format(Sys.time(), "%H:%M:%S"),"\n"); flush.console()}
+   page <- paste(durl,f,sep='')
+   M <- net2matrix(page,warn=-1)
+   if(is.na(M)){ner <- ner+1
+     cat("\n",j,"error in file",page,"\n"); flush.console(); next
+   }
+   nn <- nrow(M); Nam <- row.names(M)
+   for(u in 1:nn) for(v in u:nn){
+     if(M[u,v]!=0){
+       indu <- N[Nam[u]]; if(is.na(indu)) indu <- N[Nam[u]] <- length(N)
+       indv <- N[Nam[v]]; if(is.na(indv)) indv <- N[Nam[v]] <- length(N)
+       m <- m+1; U[m] <- indu; V[m] <- indv; W[m] <- M[u,v]
+     }
+   }
+ }
> cat("end:",format(Sys.time(), "%H:%M:%S"),"\n",ner," errors\n")
> 
> uvLab2net(names(N)[2:length(N)],U[1:m],V[1:m],W[1:m],Net="JCR07.net")
</code>

The program was interrupted
<code>
Error in file(file, "r") : cannot open the connection
</code>
To continue the network construction in the interruption point I entered a slightly changed part of the program (valid also for following interruptions)
<code>
> cat("Start:",format(Sys.time(), "%H:%M:%S"),"\n")
> F1 <- F[j:length(F)]; j <- j-1
> for(f in F1){
+   j <- j+1
...
+   }
+ }
> cat("end:",format(Sys.time(), "%H:%M:%S"),"\n",ner," errors\n")
</code>

The obtained network ''JCR*.net'' has many multiple links with different weights. In Pajek I transform it into the corresponding simple network ''JCR*s.net'' with the maximum weight on each link.


<code>
Network    Nodes    LinksC     LinksS     AvDegree
JCR4        7251    463056     109036       30.075
JCR5        7397    549421     120835       32.671
JCR6        7487    543443     119713       31.979
JCR7        7769    552335     124208       31.975
</code>

''LinksC'' is the number of links in the network ''JCR*.net'' and ''LinksS'' is the number of links in the network ''JCR*s.net''. ''AvDegree'' is the average degree in the network ''JCR*s.net''.

The Pajek NET files are available at [[https://github.com/bavla/Nets/tree/master/data/JCR|Github/Bavla]].