# Install circlize package
install.packages("circlize")

# Load circlize package
library(circlize)

# Open .csv file and save it as a matrix. 
# IMPORTANT! The first raw includes country of origin name, the first column includes destination name
mydata<-read.table(choose.files(),header = TRUE,sep = ";",stringsAsFactors =FALSE )
df<-data.frame(mydata,row.names = TRUE)
df1<-data.matrix(df)

# Default chord diagram:
chordDiagramFromMatrix(df1)

# Let's make it prettier ;) 
# Clear previous viz
circos.clear()

# Add direction
chordDiagramFromMatrix(df1,directional = -1)

# Ribbon colors should represent the flow from origin to destination
chordDiagramFromMatrix(t(df1),directional = 1)

# Add direction arrows
chordDiagramFromMatrix(t(df1),directional = 1,direction.type = "arrows")

# Add ordiering of your choice
chordDiagramFromMatrix(t(df1),directional = 1,direction.type = "arrows",
                       order = c("AT","DK","HR","BE","CZ","BG"))

# Add some space between categories
circos.clear()
circos.par(gap.after=7)
chordDiagramFromMatrix(t(df1),directional = 1,direction.type = "arrows",
                       order = c("AT","DK","HR","BE","CZ","BG"))

# Add color of your choice
circos.clear()
circos.par(gap.after=7)
grid.col = c(HR = "blue",CZ="red",DK="grey",AT="grey",BE="grey",BG="grey")
chordDiagramFromMatrix(t(df1),directional = 1,direction.type = "arrows",
                       order = c("AT","DK","HR","BE","CZ","BG"),
                       grid.col = grid.col)

# Add transparency if needed. 
# The value should between 0 to 1 in which 0 means no transparency and 1 means full transparency.
circos.clear()
circos.par(gap.after=7)
chordDiagramFromMatrix(t(df1),directional = 1,direction.type = "arrows",
                       order = c("AT","DK","HR","BE","CZ","BG"),
                       grid.col = grid.col,
                       transparency=0.7)

# If you need an arrow boarder
circos.clear()
circos.par(gap.after=7)
chordDiagramFromMatrix(t(df1),directional = 1,direction.type = "arrows",
                       order = c("AT","DK","HR","BE","CZ","BG"),
                       grid.col = grid.col,
                       transparency=0.7,
                       link.lwd = 2, link.lty = 2, link.border = "yellow")

# Orders of link according to the value - decreasing
circos.clear()
circos.par(gap.after=7)
chordDiagramFromMatrix(t(df1),directional = 1,direction.type = "arrows",
                       grid.col = grid.col,
                       transparency=0.7,
                       link.sort=TRUE,
                       link.decreasing = TRUE)

# Orders of link according to the value - increasing
circos.clear()
circos.par(gap.after=7)
chordDiagramFromMatrix(t(df1),directional = 1,direction.type = "arrows",
                       grid.col = grid.col,
                       transparency=0.7,
                       link.sort = TRUE,
                       link.decreasing = FALSE)

# To show results as %
circos.clear()
circos.par(gap.after=7)
chordDiagramFromMatrix(t(df1),directional = 1,direction.type = "arrows",
                       grid.col = grid.col,
                       transparency=0.7,
                       link.sort = TRUE,
                       link.decreasing = FALSE,
                       scale=TRUE)

# Arrows only for important links
circos.clear()
circos.par(gap.after=7)
arr.col=data.frame(c("CZ","HR"),c("AT","AT"),c("black","black"))
chordDiagramFromMatrix(t(df1),directional = 1,direction.type = "arrows",
                       link.arr.col = arr.col,
                       grid.col = grid.col,
                       transparency=0.4,
                       link.sort = TRUE,
                       link.decreasing = FALSE,
                       scale=TRUE)
# Final
circos.clear()
circos.par(gap.after=7)
grid.col = c(HR = "#00b4d8",CZ="#ffb703",DK="#f0efeb",AT="#f0efeb",BE="#f0efeb",BG="#f0efeb")
arr.col=data.frame(c("CZ","HR"),c("AT","AT"),c("black","black"))
chordDiagramFromMatrix(t(df1),directional = 1,direction.type = "arrows",
                       link.arr.col = arr.col,
                       grid.col = grid.col,
                       transparency=0.3,
                       link.sort = TRUE,
                       link.decreasing = FALSE,
                       scale=FALSE)