Week 1 Challenge Submission

Loading Data and Creating a Network

Challenge Overview

Today’s challenge is to

1. read in a dataset, and

2. create a network object

Load the Data

• Use ‘read.csv’ to read got_like_dislike.csv’ file
• Remove first columns to prepare Adjacency matrix
• Convert Dataframe to matrix format

Code

data = read.csv('_data\\got\\got_like_dislike.csv', header=TRUE)
data = data[,4:ncol(data)]
# Convert the data frame to matrix
adj_matrix <- as.matrix(data)

Create a Network

• Load the package igraph and create an igraph object,
• The network seem ‘undirected’ and ‘weighted’
• Data is an adjacency matrix format.
• ‘simplify’ is applied to remove multiple edges and combine their weights to represent the edges in a single line.
• Nodes/ Vertexes have been color coded on the basis of total sum of likes and dislikes, where if:
  • total sum of likes and dislikes >0, vertex color is green
  • total sum of likes and dislikes <0, vertex color is red
  • total sum of likes and dislikes =0, vertex color is yellow
• Edges between nodes have been color coded on the basis of like/ dislike value, where for a:
  • like, edge color is green
  • dislike, vertex color is red
  • Other, vertex color is yellow

Code

library(igraph)
# create a graph object from the adjacency matrix
graph.ig <- graph_from_adjacency_matrix(adj_matrix, mode = "undirected", diag = FALSE, weighted = TRUE)

# simplify the graph to remove multiple edges and combine their weights
graph.ig <- simplify(graph.ig, edge.attr.comb = "sum")

# add a small positive value to all edge weights to avoid layout errors
E(graph.ig)$weight <- E(graph.ig)$weight + 10

# specify color vectors based on likes/dislikes column for vertices and edges
color_vector <- ifelse(rowSums(adj_matrix, na.rm = TRUE) > 0, "green", ifelse(rowSums(adj_matrix, na.rm = TRUE) < 0, "red", "yellow"))
edge_color_vector <- ifelse(adj_matrix > 0, "green", ifelse(adj_matrix < 0, "red", "yellow"))

# plot the graph with adjusted parameters
plot(graph.ig, 
     layout=layout_with_fr(graph.ig, weights = E(graph.ig)$weight), 
     vertex.size=10, 
     vertex.label.cex=0.8, 
     vertex.label.color= 'black',
     vertex.frame.color = color_vector,
     vertex.color = color_vector,
     edge.arrow.size=0.5,
     edge.width=E(graph.ig)$weight/10,
     edge.color=edge_color_vector,
     main="Game of Thrones Likes/Dislikes Graph")