network (version 1.13.0)

loading.attributes: Examples of how to load vertex and edge attributes into networks

Description

Additional examples of how to manipulate network attributes using the functions documented in attribute.methods

Details

The attribute.methods documentation gives details about the use of the specific network attribute methods such as get.vertex.attribute and set.edge.attribute. This document gives examples of how to load in and attach attribute data, drawing heavily on material from the Sunbelt statnet workshops https://statnet.csde.washington.edu/trac/wiki/Resources.

The examples section below give a quick overview of:

• Loading in a matrix

Attaching vertex attributes

Attaching edge atributes from a matrix

Loading in an edgelist

Attaching edge atributes from an edgelist

The read.table documentation provides more information about reading data in from various tabular file formats prior to loading into a network. Note that the output is usually a data.frame object in which each columns is represented as a factor. This means that in some cases when the output is directly loaded into a network the variable values will appear as factor level numbers instead of text values. The stringsAsFactors=FALSE flag may help with this, but some columns may need to be converted using as.numeric or as.character where appropriate.

References

Acton, R. M., Jasny, L (2012) An Introduction to Network Analysis with R and statnet Sunbelt XXXII Workshop Series, March 13, 2012. https://statnet.csde.washington.edu/trac/raw-attachment/wiki/Resources/introToSNAinR_sunbelt_2012_tutorial.pdf

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/

See Also

attribute.methods, as.network.matrix, as.sociomatrix, as.matrix.network, network.extraction

Examples

# read in a relational data adjacency matrix

# LOADING IN A MATRIX
## Not run: 
# # can download matrix file from 
# # https://statnet.csde.washington.edu/trac/raw-attachment/wiki/Resources/relationalData.csv
# # and download vertex attribute file from
# # https://statnet.csde.washington.edu/trac/raw-attachment/wiki/Resources/vertexAttributes.csv
# 
# # load in relation matrix from file
# relations <- read.csv("relationalData.csv",header=FALSE,stringsAsFactors=FALSE)
# 
# # convert to matrix format from data frame
# relations <- as.matrix(relations) 
# 
# # load in vertex attributes
# nodeInfo <- read.csv("vertexAttributes.csv",header=TRUE,stringsAsFactors=FALSE)
# ## End(Not run)
          
                  
print(relations) # peek at matrix 
print(nodeInfo)  # peek at attribute data

# Since our relational data has no row/column names, let's set them now
rownames(relations) <- nodeInfo$name
colnames(relations) <- nodeInfo$name

# create undirected network object from matrix
nrelations<-network(relations,directed=FALSE)

# it read in vertex names from matrix col names ...
network.vertex.names(nrelations)

# ATTACHING VERTEX ATTRIBUTES

# ... but could also set vertex.names with 
nrelations%v%'vertex.names'<- nodeInfo$name

# load in other attributes 
nrelations%v%"age" <- nodeInfo$age
nrelations%v%"sex" <- nodeInfo$sex
nrelations%v%"handed" <- nodeInfo$handed
nrelations%v%"lastDocVisit" <- nodeInfo$lastDocVisit

# Note: order of attributes in the data frame MUST match vertex ids
# otherwise the attribute will get assigned to the wrong vertex

# check that they got loaded
list.vertex.attributes(nrelations)


# what if we had an adjaceny  matrix like:
valuedMat<-matrix(c(1,2,3, 2,0,9.5,1,5,0),ncol=3,byrow=TRUE)
valuedMat

# make a network from it
valuedNet<-network(valuedMat,loops=TRUE,directed=TRUE)

# print it back out ...
as.matrix(valuedNet)

# wait, where did the values go!!?

# LOADING A MATRIX WITH VALUES

# to construct net from matrix with values:
valuedNet<-network(valuedMat,loops=TRUE,directed=TRUE,
            ignore.eval=FALSE,names.eval='myEdgeWeight')
            
# also have to specify the name of the attribute when converting to matrix
as.matrix(valuedNet,attrname='myEdgeWeight')

# ATTACHING EDGE ATTRIBUTES FROM A MATRIX

# maybe we have edge attributes of a different sort in another matrix like:
edgeAttrs<-matrix(c("B","Z","Q","W","A","E","L","P","A"),ncol=3,byrow=TRUE)
edgeAttrs

# we can still attach them
valuedNet<-set.edge.value(valuedNet,'someLetters',edgeAttrs)

# and extract them
as.matrix(valuedNet,attrname='someLetters')
valuedNet%e%'someLetters'

# but notice that some of the values didn't get used 
# the ("A"s are missing) because there were no corresponding edges (loops)
# for the attribute to be attached to


# ATTACHING EDGE ATTRIBUTES FROM A LIST

# it is also possible to attach edge attributes directly from a list
edgeCols<-c("red","green","blue","orange","pink","brown","gray")
valuedNet<-set.edge.attribute(valuedNet,"edgeColors",edgeCols)

# but this can be risky, because we may not know the ordering of the edges,
# (especially if some have been deleted).  Does "green" go with the edge from 
# 1 to 2, or from 3 to 1?

# Usually if the edge data is only availible in list form, it is safer to construct
# the network from an edgelist in the first place

# LOADING IN AN EDGELIST

# pretend we just loaded in this data.frame from a file
elData<-data.frame(
  from_id=c("1","2","3","1","3","1","2"),
  to_id=c("1", "1", "1", "2", "2", "3", "3"),
  myEdgeWeight=c(1, 2, 1, 2, 5, 3, 9.5),
  someLetters=c("B", "W", "L", "Z", "P", "Q", "E"),
  edgeCols=c("red","green","blue","orange","pink","brown","gray"),
  stringsAsFactors=FALSE
)

# peek at data
# each row corresponds to a relationship (edge) in the network
elData

# to make a network we just use the first two id columns
valuedNet2<-network(elData[,1:2],matrix.type='edgelist')

# print it out
as.matrix(valuedNet2)

# has right edges, but no values

# to include values (with names from the columns)

valuedNet2<-network(elData,matrix.type='edgelist',ignore.eval=FALSE)
list.edge.attributes(valuedNet2)
as.matrix(valuedNet2,attrname='someLetters')