[igraph] graph.adjacency() doesn't name edge attribute as "weighted" argument

[Raffaele Vacca]

Hi,

there seem to be a little problem with the argument "weighted" in 
graph.adjacency().

According to igraph manual the "weighted" argument of that function does the 
following:
"If it is a character constant then for every non-zero matrix entry an edge is created and the value of the 
entry is added as an edge attribute named by the weighted argument. If it is TRUE then a weighted graph is 
created and the name of the edge attribute will be weight. See also details below."

However, when set at a character constant, "weighted" fails to name the edge attribute it creates. It does 
create an edge attribute with the matrix entries, but that attribute is not named after the "weighted" 
argument. It's named "weight" just like if the argument was set as "weighted= TRUE".

--------------------------------------------------------------------------------------
# Sample adjacency matrix of 5 rows and 5 columns.
# Its entries are probabilities of the edge and can be 0, 0.5 or 1.
set.seed(1234)
adjacency <- matrix(sample(c(0, 0.5, 1), size= 5*5, replace= TRUE), nrow= 5, 
ncol= 5)

# Import graph from "adjacency" and try to set the matrix entries as edge attribute named 
"prob"
graph.adjacency(adjmatrix= adjacency,
                mode= 'upper',
                weighted= 'prob',
                diag= FALSE)

# In the output value, that edge attribute is actually named "weight".
# Just like if it was "weighted= TRUE".
graph.adjacency(adjmatrix= adjacency,
                mode= 'upper',
                weighted= TRUE,
                diag= FALSE)

--------------------------------------------------------------------------------------



--
* Raffaele Vacca *
PhD candidate Urban and Local European Studies
Department of Sociology and Social Research
Università degli Studi di Milano-Bicocca
Room 208, II Floor
Via Bicocca degli Arcimboldi, 8
20126, Milano
address@hidden