Package jline.solvers.fluid.analyzers

Class DiffusionAnalyzer

java.lang.Object

jline.solvers.fluid.analyzers.DiffusionAnalyzer

All Implemented Interfaces:

FluidAnalyzer

public class DiffusionAnalyzer
extends Object
implements FluidAnalyzer

Diffusion approximation for closed multiclass BCMP networks.

Euler-Maruyama simulation of the diffusion limit. Every routing arc a -> b carries the flux phi_a(x) P(a,b), with phi = mu*x at an INF station and mu*x/max(1,n_i) at a single server (n_i the station total), plus its own Brownian noise sqrt(phi_a P(a,b) dt) Z moved from a to b, so each step conserves the chain populations exactly. A transfer that would drive a coordinate below zero is scaled down until it lands there, which keeps the population exact without re-projecting the state.

QN is the time average over the second half of the trajectory (the first is discarded as warm-up). TN is X_c * V(i,r) per chain, with X_c the mean departure rate E[phi]/V at the chain's bottleneck (largest V/mu, single servers before INF stations), so the throughputs are flow-balanced by construction; UN is TN/mu at a single server and QN at an INF station. options.timestep is the step (default 0.01); a finite options.timespan end sets the horizon, otherwise 100000 steps are taken. options.iter_max is the closing-iteration count every FLD run carries a default for, so it is not read.

Supported models: closed multiclass networks, scheduling PS / FCFS / INF / SIRO, single-server or infinite-server stations only.

IT IS A STOCHASTIC METHOD. Like SSA and LDES it draws from a seeded stream, so a run is reproducible for a fixed options.seed but agrees with MATLAB, Python and C++ in distribution only.

Port of matlab/src/solvers/FLD/solver_fluid_diffusion.m.

Constructor Summary

Constructors

Constructor	Description
DiffusionAnalyzer()

Method Summary

Modifier and Type	Method	Description
void	analyze(NetworkStruct sn, SolverOptions options, SolverResult result)
Matrix	getXVecIt()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

DiffusionAnalyzer

public DiffusionAnalyzer()

Method Details

analyze

public void analyze(NetworkStruct sn,
 SolverOptions options,
 SolverResult result)

Specified by:

analyze in interface FluidAnalyzer

getXVecIt

public Matrix getXVecIt()

Specified by:

getXVecIt in interface FluidAnalyzer