Create network objects

GAStech_graph <- 
  tbl_graph(nodes = GAStech_nodes, edges = GAStech_edges_aggregated, directed = TRUE)

GAStech_graph %>%
  activate(edges) %>%
  arrange(desc(Weight))

1.1 Improve the code chunk used to create the organisation network graph by using the latest functions provided in ggraph2.0

g_original <- GAStech_graph %>%
  mutate(betweenness_centrality = centrality_betweenness()) %>%
  mutate(closeness_centrality = centrality_closeness()) %>%
  ggraph(layout = "nicely") + 
  geom_edge_link(aes()) +
  geom_node_point(aes(colour = closeness_centrality, size=betweenness_centrality))+ theme_graph()

g_improve <-GAStech_graph %>%
  mutate(betweenness_centrality = centrality_betweenness()) %>%
  mutate(closeness_centrality = centrality_closeness()) %>%
  
  #Modified code
  qgraph(node_colour = closeness_centrality, node_size = betweenness_centrality)

g_improve

1.2 Identify three aspects of the graph visualisation in Section 6.1 that can be improved.

• Lack of labelling

  • Difficult for users to interpret information
  • No categorisation by Weekday or Department.

• The edges are difficult to identify

  • Thick edges and the black edges confuse users with the darker shades nodes.

• Nodes

  • The size of nodes is not scaled
  • Lower closeness centrality leads to darker shades.

• Colour

  • The colour of edges and nodes are not clear and hard to read

1.3 Provide the sketch of your alternative design.

1.4 Using appropriate ggraph functions, plot the alternative design.

Improvements made: * Scaling are added for edges and nodes. The reduced thickness of edges and larger nodes improve readibility. *

GAStech_graph<- GAStech_graph %>%
  mutate(betweenness_centrality = centrality_betweenness()) %>%
  mutate(closeness_centrality = centrality_closeness()) 

g <- ggraph(GAStech_graph, layout="nicely") +
  geom_edge_link0(aes(edge_width=Weight), color="grey", alpha=0.5) +
  geom_node_point(aes(colour = closeness_centrality, size=betweenness_centrality)) +
  #Scale line
  scale_edge_width_continuous(range = c(0.4,0.9))+
  #Scale nodes
  scale_size_continuous(range=c(2,8)) + 
  geom_node_text(aes(label =label), colour = "#53584C",size = 2) + 
  scale_color_gradient(low = "#F0F4C3", high = "#E14275")+
  geom_node_label(aes(filter=closeness_centrality > 0.015, label= label), repel = TRUE)+
  ggtitle("Alternative Design") 

g + theme_graph() + theme(legend.position = "right")

g <- ggraph(GAStech_graph, layout="nicely") +
  geom_edge_link0(aes(edge_width=Weight), c="grey66", alpha=0.5) +
  geom_node_point(aes(colour = closeness_centrality, size=betweenness_centrality)) +
  #Scale line
  scale_edge_width_continuous(range = c(0.5,0.9))+
  #Scale nodes
  scale_size_continuous(range=c(2,8)) + 
  scale_color_gradient(low = "#F0F4C3", high = "#E14275")+
    geom_label_repel(aes(x=ifelse(closeness_centrality > 0.015, x, 0), 
                      y=ifelse(closeness_centrality > 0.015, y, 0),
                      label=ifelse(closeness_centrality > 0.015, label,"")),
                  color = 'black',
                  size = 2,
                  box.padding = 0.50, point.padding = 0.5,
                  na.rm=TRUE) +
  ggtitle("Centrality indices Chart by Department and Weekday") 

g + facet_graph(Weekday~Department) + theme_graph()

Rename Department column to group

GAStech_nodes <- GAStech_nodes %>%
  rename(group = Department)
GAStech_nodes

2.1 Improve the design of the graph by incorporating the following interactivity:

• When a name is selected from the drop-down list, the corresponding node will not only be highlighted but also will be labelled. Furthermore, all the linked nodes of the selected node will also be labelled too.

• When a node of the interactive graph is selected, the node will not only be highlighted but also will be labelled. Furthermore, all the linked nodes of the selected node will be labelled as well.

visNetwork(GAStech_nodes, GAStech_edges_aggregated) %>%
  visNodes(font = list(size=30), 
           scaling = list(label=list(Threshold=30, maxVisible=60))) %>%
  visIgraphLayout(layout = "layout_with_fr") %>%
  visOptions(highlightNearest = list(enabled = T, degree = 0), nodesIdSelection = TRUE) 

2.2 Identify three aspects of the graph visualisation in Section 7.4 that can be improved.

• Clear label.
  • The size of label helps to aid in conveying important information and further improve readability
• Colour
  • Node colors are not defined. The color is not defined in the legend, thus it is difficult to derive any meaningful information
• Tooltips
  • Details of name, department and job title are presented to display a particular employee’s information

2.3 Provide the sketch of your alternative design.

2.4 Using appropriate visNetwork functions, plot the alternative design.

visNetwork(GAStech_nodes, GAStech_edges_aggregated) %>%
  visIgraphLayout(layout = "layout_with_fr") %>%
  visOptions(highlightNearest = list(enabled = TRUE, degree = 1, hover = TRUE), 
            selectedBy = list(variable= "group", main="Department"), 
            nodesIdSelection = list(main="Employee Name")) %>%
  visNodes(labelHighlightBold = TRUE, shape = "box", font = list(size=30)) %>%
  visLegend(position="right", zoom=FALSE) %>%
  visEdges(arrows = "to", color = list(highlight="#424242"))

GAStech_nodes$title <- paste0("<p>Name:<br>",GAStech_nodes$label,"<p>Title:<br>",GAStech_nodes$Title,"<p>group:<br>",GAStech_nodes$group)