具有igraph R的数据框的邻接矩阵

Question

I am new at R and graphs, and I am trying to practice with a social signed network using the library igraph.

I have a dataframe (df) which contains three columns. The first one is the voter, the second one the user who receives the vote, and the third one is the vote (-1 or 1 depending of the negative or positive vote, respectively).

> head(df)

     voter        user      vote
1    ludraman     cjcurrie     1
2    blankfaze    olivo       -1
3    gzornenplatz cjcurrie     1
4    orthogonal   olvion       1
5    andrevan     cerviz       1
6    texture      cjcurrie     1

I want to create a graph with igraph but firstly I need to obtain the adjacency matrix from df.

I tried with the library sharpshootR

A <- component.adj.matrix(df[, c(1,2)], mu=df[, 1], co=df[, 2], wt=df[, 3])

Is there a simple way to obtain that adjacency matrix using the library igraph?

Thanks.

Answer 1

If I got your problem right, you can use graph_from_data_frame from igraph itself:

Data

d <- structure(list(voter     = c("ludraman", "blankfaze", "gzornenplatz", "orthogonal", 
                                  "andrevan", "texture"), 
                    user      = c("cjcurrie", "olivo", "cjcurrie", "olvion", "cerviz", "cjcurrie"), 
                    vote      = c(1L, -1L, 1L, 1L, 1L, 1L)), 
                    row.names = c("1", "2", "3", "4", "5", "6"), class = "data.frame")

igraph

library(igraph)
g <- graph_from_data_frame(d)
plot(g)

You can probably work from tehre (given your full data) to use other parts of the data in the visualization (like the score).

Answer 2

This solution works for my problem:

edge_list <- training_edges[df].                # create a edge list
G <- graph.data.frame(edge_list, directed=TRUE) # create the graph

A <- as_adjacency_matrix(G,type="both",names=TRUE,
sparse=FALSE, attr = "vote")                    # create the adjacency matrix

Where A is the adjacency matrix.