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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.

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).

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.