attribute.methods: Attribute Interface Methods for the Network Class
In network: Classes for Relational Data

Description Usage Arguments Details Value Note Author(s) References See Also Examples

These methods get, set, list, and delete attributes at the network, edge, and vertex level.

delete.edge.attribute(x, attrname)
delete.network.attribute(x, attrname)
delete.vertex.attribute(x, attrname)

get.edge.attribute(el, attrname, unlist = TRUE, na.omit = FALSE, null.na = FALSE,
                                    deleted.edges.omit = FALSE)
get.edge.value(x, attrname, unlist = TRUE, na.omit = FALSE, null.na = FALSE,
                                    deleted.edges.omit = FALSE)
get.network.attribute(x, attrname, unlist = FALSE)
get.vertex.attribute(x, attrname, na.omit = FALSE, null.na = TRUE, unlist = TRUE)
network.vertex.names(x)

list.network.attributes(x)
list.edge.attributes(x)
list.vertex.attributes(x)

set.edge.attribute(x, attrname, value, e=seq_along(x$mel))
set.edge.value(x, attrname, value, e=seq_along(x$mel))
set.network.attribute(x, attrname, value)
set.vertex.attribute(x, attrname, value, v=seq_len(network.size(x)))
network.vertex.names(x) <- value

`el`	a list of edges (possibly `network$mel`), or an object of class `network` from which the full list of edges will be extracted
`x`	an object of class `network`.
`attrname`	the name of the attribute to get or set.
`unlist`	logical; should retrieved attribute values be `unlist`ed prior to being returned?
`na.omit`	logical; should retrieved attribute values corresponding to vertices/edges marked as 'missing' be removed?
`deleted.edges.omit`	logical: should the elements corresponding to deleted edges be removed?
`null.na`	logical; should `NULL` values (corresponding to vertices or edges with no values set for the attribute) be replaced with `NA`s in output?
`value`	values of the attribute to be set; these should be in `vector` or `list` form for the `edge` and `vertex` cases, or `matrix` form for `set.edge.value`.
`e`	IDs for the edges whose attributes are to be altered.
`v`	IDs for the vertices whose attributes are to be altered.

The list.attributes functions return the names of all edge, network, or vertex attributes (respectively) in the network. All attributes need not be defined for all elements; the union of all extant attributes for the respective element type is returned.

The get.attribute functions look for an edge, network, or vertex attribute (respectively) with the name attrname, returning its values. Note that, to retrieve an edge attribute from all edges within a network x, x$mel should be used as the first argument to get.edge.attribute; get.edge.value is a convenience function which does this automatically. As of v1.7.2, if a network object is passed to get.edge.attribute it will automatically call get.edge.value instead of returning NULL. When the parameters na.omit, or deleted.edges.omit are used, the position index of the attribute values returned will not correspond to the vertex/edge id. To preserved backward compatibility, if the edge attribute attrname does not exist for any edge, get.edge.attribute will still return NULL even if null.na=TRUE

network.vertex.names is a convenience function to extract the "vertex.names" attribute from all vertices.

The set.attribute functions allow one to set the values of edge, network, or vertex attributes. set.edge.value is a convenience function which allows edge attributes to be given in adjacency matrix form, and the assignment form of network.vertex.names is likewise a convenient front-end to set.vertex.attribute for vertex names. The delete.attribute functions, by contrast, remove the named attribute from the network, from all edges, or from all vertices (as appropriate). If attrname is a vector of attribute names, each will be removed in turn. These functions modify their arguments in place, although a pointer to the modified object is also (invisibly) returned.

Additional practical example of how to load and attach attributes are on the loading.attributes page.

Some attribute assignment/extraction can be performed conveniently through the various extraction/replacement operators, although they may be less efficient. See the associated man page for details.

For the list.attributes methods, a vector containing attribute names. For the get.attribute methods, a list containing the values of the attribute in question (or simply the value itself, for get.network.attribute). For the set.attribute and delete.attribute methods, a pointer to the updated network object.

As of version 1.9 the set.vertex.attribute function can accept and modify multiple attributes in a single call to improve efficiency. For this case attrname can be a list or vector of attribute names and value is a list of values corresponding to the elements of attrname (can also be a list of lists of values if elements in v should have different values).

Carter T. Butts buttsc@uci.edu

Butts, C. T. (2008). “network: a Package for Managing Relational Data in R.” Journal of Statistical Software, 24(2). http://www.jstatsoft.org/v24/i02/

loading.attributes,network, as.network.matrix, as.sociomatrix, as.matrix.network, network.extraction

#Create a network with three edges
m<-matrix(0,3,3)
m[1,2]<-1; m[2,3]<-1; m[3,1]<-1
g<-network(m)

#Create a matrix of values corresponding to edges
mm<-m
mm[1,2]<-7; mm[2,3]<-4; mm[3,1]<-2

#Assign some attributes
set.edge.attribute(g,"myeval",3:5)
set.edge.value(g,"myeval2",mm)
set.network.attribute(g,"mygval","boo")
set.vertex.attribute(g,"myvval",letters[1:3])
network.vertex.names(g) <- LETTERS[1:10]

#List the attributes
list.edge.attributes(g)
list.network.attributes(g)
list.vertex.attributes(g)

#Retrieve the attributes
get.edge.attribute(g$mel,"myeval")  #Note the first argument!
get.edge.value(g,"myeval")          #Another way to do this
get.edge.attribute(g$mel,"myeval2") 
get.network.attribute(g,"mygval")
get.vertex.attribute(g,"myvval")
network.vertex.names(g)

#Purge the attributes
delete.edge.attribute(g,"myeval")
delete.edge.attribute(g,"myeval2")
delete.network.attribute(g,"mygval")
delete.vertex.attribute(g,"myvval")

#Verify that the attributes are gone
list.edge.attributes(g)
list.network.attributes(g)
list.vertex.attributes(g)

#Note that we can do similar things using operators
g %n% "mygval" <- "boo"               #Set attributes, as above
g %v% "myvval" <- letters[1:3]
g %e% "myeval" <- mm
g[,,names.eval="myeval"] <- mm          #Another way to do this
g %n% "mygval"                        #Retrieve the attributes
g %v% "myvval"
g %e% "mevval"
as.sociomatrix(g,"myeval")              # Or like this