Uploading Assignment 3-Yanyi Zhang

Assignment 3.Rmd

@@ -34,7 +34,7 @@ Since our data represnts every time a student makes a comment there are multiple
 
 EDGE <- count(D2, comment.to, comment.from)
 
-names(EDGE) <- c("from", "to", "count")
+names(EDGE) <- c("to", "from", "count")
 
 ```
 
@@ -104,12 +104,23 @@ In Part II your task is to [look up](http://igraph.org/r/) in the igraph documen
 
 * Ensure that sizing allows for an unobstructed view of the network features (For example, the arrow size is smaller)
 * The vertices are colored according to major
-* The vertices are sized according to the number of comments they have recieved
+* The vertices are sized according to the number of comments they have received
+
+
+```{r}
+names(EDGE) <- c("comment.from", "count")
+
+
+plot.igraph(g,  layout=layout.fruchterman.reingold, vertex.color = VERTEX$major, vertex.label.font = 0.03, vertex.size = 8, vertext.lable.cex = 0.01, vertex.label.dist=2, edge.arrow.size=0.3, edge.curved=0, edge.width=0.5)
+```
+
+
 
 ## Part III
 
 Now practice with data from our class. This data is real class data directly exported from Qualtrics and you will need to wrangle it into shape before you can work with it. Import it into R as a data frame and look at it carefully to identify problems.
 
+
 Please create a **person-network** with the data set hudk4050-classes.csv. To create this network you will need to create a person-class matrix using the tidyr functions and then create a person-person matrix using `t()`. You will then need to plot a matrix rather than a to/from data frame using igraph.
 
 Once you have done this, also [look up](http://igraph.org/r/) how to generate the following network metrics:
@@ -118,6 +129,54 @@ Once you have done this, also [look up](http://igraph.org/r/) how to generate th
 
 * Color the nodes according to interest. Are there any clusters of interest that correspond to clusters in the network? Write a sentence or two describing your interpetation.
 
+```{r}
+library(tidyr)
+library(dplyr)
+library(stringr)
+library(igraph)
+
+C1 <- read.csv("hudk4050-classes.csv", stringsAsFactors = FALSE, header = TRUE)
+C2 <- C1
+colnames(C2) <- C2[1,]
+C2 <- slice(C2, 3:49)
+C2 <- select(C2, 1:8)
+C2 <- unite(C2, "name", 'First Name', 'Last Name', sep = " ")
+C2$name <- str_replace(C2$name, "'", "")
+C2$name <- str_to_title(C2$name)
+C2 <- C2 %>% mutate_at(2:7, list(toupper))
+C2 <- C2 %>% mutate_at(2:7, str_replace_all, " ","")
+C3 <- C2 %>% gather(label, class, 2:7, na.rm = TRUE, convert = FALSE) %>% select(name, class)
+
+C3$count <- 1
+C3 <- filter(C3, class != "")
+C3 <-unique(C3)
+C3 <- spread(C3, class, count)
+rownames(C3) <- C3$name
+C3 <- select(C3, -name, -HUDK4050)
+C3[is.na(C3)] <- 0
+C4 <- as.matrix(C3)
+C4 <- C4 %*% t(C4)
+
+g <- graph.adjacency(C4, mode="undirected", diag = FALSE)
+plot(g, layout=layout.fruchterman.reingold, vertex.size = 5, vertex.label.cex=0.7)
+
+sort(degree(g), decreasing = TRUE)
+sort(betweenness(g), decreasing = TRUE)
+
+
+```
+* Betweeness centrality and dregree centrality. **Who is the most central person in the network according to these two metrics? Write a sentence or two that describes your interpretation of these metrics**
+
+#Yifei Zhang is the most central person in the network since the she has high betweeness centrality and degree centrality
+
+* Color the nodes according to interest. Are there any clusters of interest that correspond to clusters in the network? Write a sentence or two describing your interpetation.
+```{r}
+plot(g, layout = layout.fruchterman.reingold, vertex.color = as.factor(C2$Interest), vertex.size = 4, vertex.label.cex= 0.7)
+```
+
+
+#There are no clusters of interest since the the colors of the nodes are different.
+
 ### To Submit Your Assignment
 
-Please submit your assignment by first "knitting" your RMarkdown document into an html file and then comit, push and pull request both the RMarkdown file and the html file.
+Please submit your assignment by first "knitting" your RMarkdown document into an html file and then comit, push and pull request both the RMarkdown file and the html file.