adjacency.md
In igraph: Network Analysis and Visualization

graph_from_adjacency_matrix() snapshot

Code
  igraph_opt("print.id")
Output
  [1] FALSE
Code
  m <- matrix(c(0, 2.5, 0, 0), ncol = 2)
  m
Output
       [,1] [,2]
  [1,]  0.0    0
  [2,]  2.5    0
Code
  graph_from_adjacency_matrix(m)
Output
  IGRAPH D--- 2 2 -- 
  + edges:
  [1] 2->1 2->1
Code
  graph_from_adjacency_matrix(m, mode = "undirected")
Condition
  Warning:
  The `adjmatrix` argument of `graph_from_adjacency_matrix()` must be symmetric with mode = "undirected" as of igraph 1.6.0.
  i Use mode = "max" to achieve the original behavior.
Output
  IGRAPH U--- 2 2 -- 
  + edges:
  [1] 1--2 1--2
Code
  graph_from_adjacency_matrix(m, mode = "max")
Output
  IGRAPH U--- 2 2 -- 
  + edges:
  [1] 1--2 1--2
Code
  graph_from_adjacency_matrix(m, weighted = TRUE)
Output
  IGRAPH D-W- 2 1 -- 
  + attr: weight (e/n)
  + edge:
  [1] 2->1
Code
  graph_from_adjacency_matrix(m, weighted = "w")
Output
  IGRAPH D--- 2 1 -- 
  + attr: w (e/n)
  + edge:
  [1] 2->1
Code
  m2 <- structure(c(0, 0.00211360121966095, 0.00211360121966098, 0), dim = c(2L,
    2L))
  graph_from_adjacency_matrix(m2, mode = "undirected")
Condition
  Warning:
  The `adjmatrix` argument of `graph_from_adjacency_matrix()` must be symmetric with mode = "undirected" as of igraph 1.6.0.
  i Use mode = "max" to achieve the original behavior.
Output
  IGRAPH U--- 2 0 -- 
  + edges:
Code
  graph_from_adjacency_matrix(1)
Condition
  Warning:
  The `adjmatrix` argument of `graph_from_adjacency_matrix()` must be a matrix as of igraph 1.6.0.
Output
  IGRAPH D--- 1 1 -- 
  + edge:
  [1] 1->1
Code
  graph_from_adjacency_matrix(1, mode = "undirected")
Condition
  Warning:
  The `adjmatrix` argument of `graph_from_adjacency_matrix()` must be a matrix as of igraph 1.6.0.
Output
  IGRAPH U--- 1 1 -- 
  + edge:
  [1] 1--1

graph_from_adjacency_matrix() snapshot for sparse matrices

Code
  igraph_opt("print.id")
Output
  [1] FALSE
Code
  m <- Matrix::sparseMatrix(2, 1, x = 2.5, dims = c(2, 2))
  m
Output
  2 x 2 sparse Matrix of class "dgCMatrix"

  [1,] .   .
  [2,] 2.5 .
Code
  graph_from_adjacency_matrix(m)
Output
  IGRAPH D--- 2 2 -- 
  + edges:
  [1] 2->1 2->1
Code
  graph_from_adjacency_matrix(m, mode = "undirected")
Condition
  Warning:
  The `adjmatrix` argument of `graph_from_adjacency_matrix()` must be symmetric with mode = "undirected" as of igraph 1.6.0.
  i Use mode = "max" to achieve the original behavior.
Output
  IGRAPH U--- 2 2 -- 
  + edges:
  [1] 1--2 1--2
Code
  graph_from_adjacency_matrix(m, mode = "max")
Output
  IGRAPH U--- 2 2 -- 
  + edges:
  [1] 1--2 1--2
Code
  graph_from_adjacency_matrix(m, weighted = TRUE)
Output
  IGRAPH D-W- 2 1 -- 
  + attr: weight (e/n)
  + edge:
  [1] 2->1
Code
  graph_from_adjacency_matrix(m, weighted = "w")
Output
  IGRAPH D--- 2 1 -- 
  + attr: w (e/n)
  + edge:
  [1] 2->1
Code
  m2 <- Matrix::sparseMatrix(2:1, 1:2, x = c(0.00211360121966095,
    0.00211360121966098))
  graph_from_adjacency_matrix(m2, mode = "undirected")
Condition
  Warning:
  The `adjmatrix` argument of `graph_from_adjacency_matrix()` must be symmetric with mode = "undirected" as of igraph 1.6.0.
  i Use mode = "max" to achieve the original behavior.
Output
  IGRAPH U--- 2 0 -- 
  + edges:

graph_from_adjacency_matrix errors for NAs

Code
  graph_from_adjacency_matrix(A)
Condition
  Error in `graph_from_adjacency_matrix()`:
  ! Cannot create a graph object because the adjacency matrix contains NAs.