Plotting Internal PageRank with 1 to 10 map function

plot-internal-pr.r

library("igraph")
internallinks <- read.csv("C:/Users/username/folder/screamingfrog-all-inlinks.csv")
g <- graph.data.frame(internallinks)
pr <- page.rank(g, algo = "prpack", vids = V(g), directed = TRUE, damping = 0.85)
values <- data.frame(pr$vector)
write.csv(values, file = "output-pagerank.csv")

map <- function(x, range = c(0,1), from.range=NA) {
    if(any(is.na(from.range))) from.range <- range(x, na.rm=TRUE)
    
    ## check if all values are the same
    if(!diff(from.range)) return(
	    matrix(mean(range), ncol=ncol(x), nrow=nrow(x), 
		    dimnames = dimnames(x)))
    
    ## map to [0,1]
    x <- (x-from.range[1])
    x <- x/diff(from.range)
    ## handle single values
    if(diff(from.range) == 0) x <- 0 
    
    ## map from [0,1] to [range]
    if (range[1]>range[2]) x <- 1-x
    x <- x*(abs(diff(range))) + min(range)
    
    x[x<min(range) | x>max(range)] <- NA
    
    x
}

plot(g, 
     layout=layout.fruchterman.reingold,
     vertex.size        = map(pr$vector, c(1,10)),
     vertex.label       = NA,      
     vertex.label.color = "black",
     edge.arrow.size=.2
)