phi_init: Simple initialization for phi in model of Cao et al. (2000)
Description
Uses a crude estimator to get a starting point for phi in
the model of Cao et al. (2000).
Usage
phi_init(Y, A, lambda0, c)
Arguments
Y
matrix (n x k) of observed link loads over time
A
routing matrix (m x k)
lambda0
numeric vector (length k) of initial
guesses for lambda
c
power parameter in model of Cao et al. (2000)
Value
numeric starting value for phi
References
J. Cao, D. Davis, S. Van Der Viel, and B. Yu. Time-varying
network tomography: router link data. Journal of the
American Statistical Association, 95:1063-75, 2000.