toaster (version 0.5.5)

computeGraphHistogram: Compute various statistic distributions on graph edges and vertices.

Description

Compute various statistic distributions on graph edges and vertices.

Usage

computeGraphHistogram(channel, graph, type = "degree", weight = FALSE, binMethod = "manual", numbins = NULL, binsize = NULL, startvalue = NULL, endvalue = NULL, vertexWhere = graph$vertexWhere, edgeWhere = graph$edgeWhere, allTables = NULL, test = FALSE, ...)

Arguments

channel

connection object as returned by odbcConnect

graph

an object of class 'toagraph' referencing graph tables in Aster database.

type

choose between graph measures to compute histogram distribution for: 'degree', 'clustering', 'shortestpath', 'pagerank', 'betweenness', 'eigenvector'.

weight

logical or character: if logical then TRUE indicates using 'weight' edge attribute, otherwise no weight used. If character then use as a name for the edge weight attribute. The edge weight may apply with types 'clustering', 'shortestpath' and centrality measures.

binMethod

one of several methods to determine number and size of bins: 'manual' indicates to use paramters below, both 'Sturges' or 'Scott' will use corresponding methods of computing number of bins and width (see http://en.wikipedia.org/wiki/Histogram#Number_of_bins_and_width).

numbins

number of bins to use in histogram.

binsize

size (width) of discrete intervals defining histogram (all bins are equal).

startvalue

lower end (bound) of values to include in histogram.

endvalue

upper end (bound) of values to include in histogram.

vertexWhere

SQL WHERE clause limiting data from the vertex table. This value when not null overrides corresponding value vertexWhere from graph (use SQL as if in WHERE clause but omit keyword WHERE).

edgeWhere

SQL WHERE clause limiting data from the edge table. This value when not null overrides corresponding value edgeWhere from graph (use SQL as if in WHERE clause but omit keyword WHERE).

allTables

pre-built information about existing tables.

test

logical: if TRUE show what would be done, only (similar to parameter test in RODBC functions: sqlQuery and sqlSave).

...

other arguments passed on to Aster graph functions except for EDGEWEIGHT argument - use argument weight instead. Aster function areguments are not casesensetive

Examples

if(interactive()) {

policeGraphUn = toaGraph("dallaspolice_officer_vertices", "dallaspolice_officer_edges_un", 
                         directed = FALSE, key = "officer", 
                         source = "officer1", target = "officer2", 
                         vertexAttrnames = c("offense_count"), edgeAttrnames = c("weight"))
               
# initialize connection to Lahman baseball database in Aster 
conn = odbcDriverConnect(connection="driver={Aster ODBC Driver};
                         server=<dbhost>;port=2406;database=<dbname>;uid=<user>;pwd=<pw>")
                         
hdegreePolice = computeGraphHistogram(conn, policeGraphUn, type='degree', numbins=36) 
createHistogram(hdegreePolice, 
                title = "Dallas Police Graph Degree Distribution", 
                xlab='Degree', ylab='Count')

hshortestpathPolice = computeGraphHistogram(conn, policeGraphUn, type='shortestpath',
                              numbins = 10)
createHistogram(hshortestpathPolice, 
                title = "Dallas Police Shortest Path Distribution", 
                xlab = "Distance", ylab = "Count")
}