ChordDiagram.Rmd

---
title: "Chord Diagram"
output:
  html_notebook: default
  html_document:
    df_print: paged
  pdf_document: default
---
```{r}
install.packages('circlize')
```

```{r}
data <- matrix(c(0, 0, 0, 0, 151, 9945, 177, 224, 0, 0, 0, 0, 1, 22, 1, 6, 171, 10883, 97, 437, 1592, 98967, 1121, 4316, 276, 11724, 102, 599, 1409, 92759, 1277, 3882), nrow = 4, ncol = 8)
data <- t(data)
colnames(data) <- (c('Bitbucket', 'GitHub', 'GitLab', 'SourceForge'))
rownames(data) <- (c('Economics', 'Statistics', 'EESS', 'Quant. Fin.', 'Quant. Bio.', 'CS', 'Math', 'Physics'))
library(circlize)
chordDiagram(data, annotationTrack = "grid", preAllocateTracks = list(track.height = 0.1))
circos.trackPlotRegion(track.index = 1, panel.fun = function(x,y) {
  xlim = get.cell.meta.data("xlim")
  xplot = get.cell.meta.data("xplot")
  ylim = get.cell.meta.data("ylim")
  sector.name = get.cell.meta.data("sector.index")
  
  if(abs(xplot[2] - xplot[1]) < 20) {
    circos.text(mean(xlim), ylim[1], sector.name, facing = "clockwise", niceFacing = TRUE, adj = c(0, 0.5))
  } else {
    circos.text(mean(xlim), ylim[1], sector.name, facing = "inside", niceFacing = TRUE, adj = c(0.5, 0))
  }
}, bg.border = NA)
```