R_estep

numeric vector (length k) of mean OD flows
  from last M-step

lambda

numeric scalar scale for covariance matrix of
  xt

routing matrix (m x k) for network being
  analyzed

power parameter in model of Cao et al. (2000)

numeric nugget to add to diagonal of
  covariance for numerical stability

epsilon


Computes conditional covariance of OD flows for E-step of
EM algorithm from Cao et al. (2000) for their locally IID
model.


networkTomography implements the methods developed and evaluated in
Blocker and Airoldi (2011) and Airoldi and Blocker (2012). These include the
authors' own dynamic multilevel model with calibration based upon a Gaussian
state-space model in addition to implementations of the methods of Tebaldi &
West (1998; Poisson-Gamma model with MCMC sampling), Zhang et al. (2002;
tomogravity), Cao et al. (2000; Gaussian model with mean-variance relation),
and Vardi (1996; method of moments). Data from the 1router network of Cao et
al. (2000), the Abilene network of Fang et al. (2007), and the CMU network
of Blocker and Airoldi (2011) are included for testing and reproducibility.

R_estep: Compute conditional covariance matrix for EM algorithms of Cao et al. (2000)

Description

Usage

Arguments

Value

References

See Also