如何修正趋势线到情节？

Question

我试图用趋势线做一个情节，但我得到了这个：https://imgur.com/a/xeAI1

如何修正趋势线？

提前致谢

library("igraph")
tfile<-tempfile()
download.file("http://pdg.cnb.uam.es/pazos/tmp/Yeast_int.txt", tfile)
datosraw <- subset(read.delim(tfile, sep="\t", header=F, stringsAsFactors = F), !is.na(V3) & V3!="" & V3!="METHOD")
names(datosraw)<-c("orf1","orf2","method")
datos<-split(datosraw,datosraw$method)
df.y2h <- graph.data.frame(d = datos$Y2H[1:5125,c(1,2)], directed = FALSE)
plot_degree_distribution = function(graph) {
  # calculate degree
  d = degree(graph, mode = "all")
  dd = degree.distribution(graph, mode = "all", cumulative = FALSE)
  degree = 1:max(d)
  probability = dd[-1]
  # delete blank values
  nonzero.position = which(probability != 0)
  probability = probability[nonzero.position]
  degree = degree[nonzero.position]
  # plot
  plot(probability ~ degree, log = "xy", xlab = "Degree (log)", ylab = "Probability (log)", 
       col = 1, main = "Degree Distribution")
  mod <- (lm(log10(probability) ~ log10(degree)))
  abline((mod), col="red")
  coef(mod)[2]
    }

plot_degree_distribution(df.y2h)