Learn R Programming

networkTomography (version 0.3)

obj.tomogravity: Objective function of Zhang et al. 2003

Description

Requires bounded optimization to maintain positive OD flows, and only those flows that are not deterministically zero should be included in the estimation.

Usage

obj.tomogravity(xt, yt, A, srcDstInd, lambda)

Arguments

xt
length-k numeric vector of point-to-point flows
yt
length-m numeric vector of observed aggregate flows
A
m x k routing matrix, yt = A xt
srcDstInd
list of source and destination flow indices corresponding to each point-to-point flow, as produced by getSrcDstIndices
lambda
regularization parameter for mutual information prior. Note that this is scaled by the squared total traffic in the objective function before scaling the mututal information prior.

Value

numeric value of objective function to minimize in tomogravity estimation