I have been watching Eurovision competitions for several years. I personally think the voting results from Eurovision competitions can be a very good source for the research of relationships between European countries. In this blog post, I will create a social network R visual using iGraph package and use the visual to analyse the voting network of Eurovison competitions.
Firstly, we need to prepare our raw Eurovision dataset into the following format that contains three columns, “From country” (where is the vote from), “To Country” (where is the vote to), and “Avg Point” (that computes the average points the “From country” has given to the “To Country” over the years. You can prepare the data either using DAX (creating the “AvgPoint” measure) or Power Query (group by “From country”+”To Country” and calculate average points).
We add a R visual to the Power BI canvas and add the three columns to the R visual. If you prefer to use other R IDE (e.g., RStudio) to edit the R scripts, you can bind your IDE to Power BI.
We will use the igraph R package to render the voting network chart. Firstly, we need to load igraph library and then create a igraph data frame from the dataset specified on the Power BI R visual. We will use the plot function to render the network chart with the style attribute settings of vertex, edge etc.
# user igraph library library(igraph) # create a igraph data frame from the dataset specified on the Power BI R visual df.g <- graph.data.frame(d = dataset, directed = TRUE) # define colors comps <- components(df.g)$membership colbar <- rainbow(max(comps)+1) V(df.g)$color <- colbar[comps+1] # render the network chart and set the style attributes of vertex, edge etc. plot(df.g, vertex.label = V(df.g)$name, layout=layout_with_fr, vertex.size=12, vertex.label.dist=0, vertex.label.color= "darkblue", vertex.shape = "circle", vertex.label.cex = 1, vertex.label.font = 2, edge.arrow.size=0.5, edge.curved=T, margin =-0.05 )
After we authored and tested the R script in RStudio, we can now add the script to the R visual in Power BI that will be able to interact with other visuals on the same page.
Before we set any threshold on the average voting points, all voting paths between the countries will be draw on the network chart that makes the chart unreadable.
However, when we set a higher average voting points as threshold which only shows the voting path over the threshold, we can find some relationship patterns.
For example, we can see the mutual high votes between neighbour countries like Spain <-> Andorra, Roumania <-> Moldova, and Greece<->Cyprus.
Please find the pbix file here.